An internal T-Mobile screenshot leaked to TMoNews states that the iOS update will not only authorize the T-Mobile network (T-Mo’s 2G and a portion of its HSPA+ networks are already supported), but will enable Apple’s visual voicemail and MMS features on the carrier as well. Here’s the text of document:

“The T-Mobile Carrier Update is a minor iOS software update that enables official iPhone support by T-Mobile. When installed, the software update enables a handful of capabilities like Visual Voicemail, MMS Settings and Network/Device optimizations that customers do not have access to today. On April 5, the software update will begin being pushed via OTA to all iPhone devices on the T-Mobile network with iOS 6.1.x or higher.”

I asked Apple and was told it isn’t commenting on a rumor, so I suppose we’ll have to wait until Friday to see if an iOS update shows up in iTunes.

Keep in mind that only the North American GSM iPhone 5 model will work on T-Mobile’s LTE systems, which are now live in seven markets, and to connect to T-Mo you must have an unlocked device. All generations of iPhones will work in T-Mobile’s 2G footprint and on its HSPA+ networks in about 50 markets today. The carrier is expanding that HSPA+ support quickly as it undergoes a major network overhaul.

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T-Mo News spotted the details, which explain what’s actually in the software. The pair of bug fixes includes corrections for when Exchange calendar events don’t appear and issues with swiping through Gmail messages. Not that those aren’t important, but they’ll likely play second fiddle to the new multi-window addition.

If all goes according to plan, Galaxy Note 2 owners on T-Mobile’s network will see the feature added this Wednesday. While some manufacturer-specific add-ons are gimmicky, the multiwindow function and floating dock can actually be useful for multitaskers. And it truly differentiates the Galaxy Note 2 — as well as some Galaxy S III devices that will have the feature — not just from other Android phones, but from all other smartphones on the market.

Not everyone will want or use it of course, but for those desiring such a feature, there’s really only one game in town: Samsung. I’ve used it more than than I thought I would on my international Galaxy Note 2, which received the software in early October. Out of the top four U.S. carriers, T-Mobile is the third to add the feature; Sprint and Verizon Galaxy Note 2 handsets already have it, leaving AT&T as the lone holdout for now.

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The reason Samsung offered for last week’s pronouncement had little do with Android 4.0 or the devices in question. Rather, the company’s own TouchWiz software, a customized user interface for Android, wouldn’t be able to fit alongside ICS on the smartphone or tablet. When the news hit, I offered a potential solution:

My suggestion would be a compromise of sorts: Offer a stock version of Android 4.0 for these devices with the customer understanding and accepting the fact that the TouchWiz interface will no longer be available after the upgrade. Unless there’s a real technical reason for the lack of an Android 4.0 upgrade — something Samsung should make clear — this might be the best answer. It wouldn’t cost nearly as much for Samsung to develop and test, while consumers thinking Samsung has let them down might be more accepting of the situation.

I don’t expect Samsung to take this route if it does deliver the software upgrade. Instead, it’s more likely the company removes a few apps or features from the software update and instead offers them as installable downloads to free up the needed space for Android 4.0 and TouchWiz.

After using Android 4.0 on an unlocked GSM Galaxy Nexus for the past four weeks, however, I’m not sure there’s much of a need for Samsung’s TouchWiz interface. Google has vastly improved the Android experience; enough so that average consumers can get by without a custom interface. I like TouchWiz; I’ve used it for a year on my own Galaxy Tab, and it helps Samsung differentiate its mobile devices from competitors. But it’s not so good that it should hold up Android 4.0 on devices that are capable of running Google’s stock software.

Regardless of what Samsung decides, there’s still another aspect of the situation that’s unknown: network operators. It’s very possible — indeed, likely, given mobile phone history — that Samsung solves this problem only to have some carriers not support it. Of course, at that point, Samsung can simply point the finger at those carriers, who are really the organizations that own the end-user customer relationship for mobile device users on contract.

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The good news is that Amazon has rethought its approach. With the new Kindle Fire software update, made available on Wednesday, you can now browse to the Google Android Market website. After I installed the software update to the Fire – we have complete instructions on the five-minute process here — I verified the browsing block was gone. I did get a security certificate warning, but was able to continue in the Fire’s browser with no other issues.

Does this mean you can now install Android Market apps to the Kindle Fire over the web? Not exactly, because there’s no simple way to associate the Kindle Fire with a Google account, which is how Google’s web-based Android Market links to devices. Regardless, this step was the right one for Amazon to take because it allows people to see which Android apps Google does offer, and it no longer hijacks the web page a user wants to view.

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The software update, version 6.2.1, is available for download directly from Amazon here. Using the Kindle Fire’s web browser to navigate there, you’ll see a Download link. Tap the link to download the 182 MB file to your Fire, which will place it in the Downloads folder. Unfortunately, the update file needs to be in the KindleUpdates folder on the device; that’s where a file explorer application comes in handy.

Using Amazon’s AppStore on the Kindle, search for “file explorer” to see what third-party apps might help in this situation. I chose AndroXplorer, which was free, and installed it. With this app, or any other comparable file explorer software, it’s simply a matter of copying the update file from the Downloads folder to the KindleUpdates folder on the Fire. Note that both of these are actually sub-folders of the sdcard folder.

Once you’ve copied the downloaded update file to the appropriate folder, go into the Settings of your Kindle Fire. Tap the Device option, and you should now see the “Update your Kindle” button lit up. Tap it to update your Kindle Fire software, which should only take a few minutes. After the device reboots, you’re all set!

As far as the update itself, it addresses several of issues found in the Kindle Fire. For starters, the device is noticeably more responsive and easier to use with the carousel interface: icons snap into place much faster. You can also customize which icons appear in the carousel. And there’s a new password lock function that secures the device so kids and others can’t easily purchase items from your Kindle Fire. I’ve only just begun using the new software update, but so far, I think most Kindle Fire owners will see this update as an early holiday present.

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Apple TV users can also grab iOS 4.4 for Apple TV (2nd gen models) now, which allows you to use AirPlay Mirroring.

In addition to users who will be downloading iTunes 10.5, released yesterday, in order to be able to install iOS 5 on their devices, the amount of software flowing from Apple’s servers as users upgrade this morning will likely put a heavy strain on its backend infrastructure. Hopefully Apple’s new massive N.C. data center helps it keep up with demand, but don’t be surprised if you have trouble connecting or encounter download delays.

Both iOS 5 and iCloud represent major changes and additions to your Mac and iOS device experience, so we have extensive coverage of both planned for the rest of the day. Stay tuned as we explain various features and also take you through the process of setting many of them up.

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Version 1.2 of the iPod nano software brings improved fitness features (which are better able to detect and track walking or running work outs), as well as the new single icon scrolling interface, which replaces the 4×4 icon grid. You can switch back to small icons or turn off home screen items altogether from the Settings menu.

Last but not least, you’ll get access to all the new iPod nano clock face options. There are 18 to choose from, so you shouldn’t get bored too quickly. I recommend the partial skeleton face with the exposed animated “movement” and second sub-dial.

The update adds a bit of individual personality for users and some very useful features, so it’s a nice free bonus arising from Tuesday’s festivities for existing iPod nano owners. Go ahead and grab it now by plugging your iPod into your computer and opening iTunes. If you don’t get prompted automatically, just hit the “Check for Updates” button in the iPod’s info screen.

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New owners of the latest Air and Mac mini will find fixes for issues related to flickering screens, booting problems when the power cord is attached, and slow running SD cards. Specifically, Apple says the update will:

• Address an issue that may cause the system to become unresponsive when playing a video in Safari
• Resolve an issue that may cause system audio to stop working when using HDMI or optical audio out
• Improve the reliability of Wi-Fi connections
• Resolve an issue that prevents transfer of your data, settings, and compatible applications to a new Mac running OS X Lion
• Resolve an issue where MacBook Air may boot up when MagSafe Adapter is attached
• Resolve an issue causing intermittent display flickering on MacBook Air
• Resolve an issue that causes the SD card slot in Mac mini to run at reduced speed with SD and SDHC media

If you have Lion, but not on one either the Mac mini or the Air, you’ll get a separate update that only pertains to the first four issues listed above.

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The OSX.MacDefender.A definition has been added to the OS X File Quarantine database, which means if a user downloads the malware, it will automatically pop up a dialog warning the user that the file will damage your computer, and provide an option to delete the file. The update also allows Apple to automatically update the known malware definitions list through daily updates. Users can opt out of this feature in Security Preferences, shown below.

The security update also automatically searches for and removes Mac Defender and its known variants upon install. If it detects the malware in your system, it will notify you once the update is installed.

It’s great to see Apple getting out ahead of this malware threat before it really gets out of hand, but as always, the first step to protecting your computer starts with you. Don’t ever install something when you’re not sure that it comes from trustworthy origins, and remember that if a website is telling you you’re infected without you having asked to begin with, it’s a safe bet that it’s not a genuine report.

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The update, which was reported to be arriving sometime within two weeks from April 7 by BGR, is also rumored to possibly bring fixes for roaming issues some Verizon iPad 2 owners are experiencing, but Apple makes no mention of the problem in its update notes for iOS 4.3.2.

The updates are compatible with the iPad, iPad 2, iPhone 3GS and 4 and the 3rd and 4th gen iPod touch. If you’re installing these updates today, please let us know in the comments how the new software is working out for you, and if you’re a Verizon iPad owner experiencing the roaming bug, whether or not 4.3.2 provides a fix.

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