In February, we took a look at smaller changes in the pre-release version of OS X Mountain Lion that Mac developers are using. These changes are good indications of what we’ll see when the final version goes live sometime this summer. Apple has released two new previews since then with quite a few updates — some significant, some seriously minor, and some that have even undone changes since we last wrote about it.

Here’s what’s new:

General changes

• The App Store now supports automatic downloads, which is one of the things I’d hoped Apple would add. You can also go backward and forward in the App Store and Game Center with two fingers, the same as Safari. Notably, you still can’t do this in the Finder.
• There’s a new popover for choosing avatars, which is used in Game Center and the Users and Groups pane in System Preferences.
• You can no longer remove apps and stacks from the Dock by simply dragging them off. You have to do it by right-clicking, which I expect is going to draw the ire of many power users.
• Launchpad is no longer arranged alphabetically. The “Utilities” folder has also been renamed to “Others”.
• The linen background in Mission Control is slightly darker than in Lion.
• Font Book now has a full-screen mode and two smart folders in the sidebar for fixed-width fonts and monospaced fonts.
• The battery item in the menu bar has been simplified so that the only option is to show the percentage left or not. Showing time left has been removed.
• You can go from one stack to another in the Dock with one click. In Lion, clicking another stack with one already open just closes the current stack. (Updated: Sorry, this isn’t new to Mountain Lion. Turns out, it doesn’t work in Lion when your Dock is hidden — which mine was — but does when unhidden.)

Safari

• There’s a new button for iCloud tabs, which allows access to tabs on other devices.
• There’s a new page-loading animation, which you can see in this YouTube video.
• Web apps can send native notifications through Safari, as evidenced by the new Notification Center tab in Safari’s preferences.
• Reading List has a new look, with a more neutral background color and paper texture instead of linen. It also supports offline reading.
• When you download a file in Safari in Lion, the file flies into the downloads button. In Mountain Lion, it flies into the downloads stack in the Dock, and a progress indicator appears over the stack.
• Safari has a more “responsive” UI: when you resize a window past a certain point, buttons will be hidden to save space.
• There’s a new tab button next to the bookmarks bar when only one tab is open and the tab bar is hidden.

Notification Center

• There’s a new “do not disturb” mode, which disables notifications when active.
• The menu bar icon has a gray dot in the middle, rather than black. It also changes into a moon when do not disturb mode is on.
• There’s a new button in the lower-righthand corner that’ll take you to Notification Center’s preference pane in System Preferences.

System Preferences

• The General perefence pane has been simplified. The options for smooth scrolling and double-click to minimize are gone, with the latter being moved to the Dock preference pane. The three dropdowns for the number of recent items has been consolidated into one. The dropdown for choosing the sidebar icon size has been moved to the top section. Finally, there’s a new checkbox for “Ask to keep changes when closing documents.”
• The preferences for “tap to click” have been moved into the Trackpad pane and are enabled by default.
• The Mission Control pane now has the option to disable grouping windows by application, so all windows will be shown the same way.
• Time Machine’s pane has been updated slightly, with flatter buttons and a simpler explanation of what Time Machine does.

What do you think of the new changes? Tell us in the comments.

Header image via Flicker user sigsegv.

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• New challenges for the IT organization
• The new IT manager, part 1
• Tablet market to hit over 377 million units by 2016

Yesterday evening was a red-letter night for Apple developers, especially if you happened to have both Mac and iPhone developer accounts. That’s because Apple dropped new builds of both iPhone OS 3.1 and Snow Leopard, bringing it to version 10A411. Users with an iPhone developer account can head to Apple’s Developer Connection web site and get iPhone 3.1 Beta 2 and its attendant SDK in the usual way, while Snow Leopard users should find the new build available when they open up Software Update.

iPhone OS 3.1 Beta 2

I wasn’t expecting any massive changes in an incremental decimal point update, and a Beta 2 at that, but apparently this latest build packs at least one big punch. Said punch is the ability for developers to communicate with their device wirelessly while debugging new apps and versions, over Wi-Fi. It’s not something end users will ever see or necessarily appreciate, but it’s hard to understate how much it helps on the development side not to have to depend on a hardware tether anymore.

Theoretically, at least, this clears up the dock connector for use with third-party peripherals that tap into OS 3.0′s new software access features. Hopefully that gets more developers working faster on integrated hardware devices, since it’s the one remaining OS 3.0 feature that has yet to see its potential realized.

One “feature” not everyone will be pleased with is the new beta’s built-in tethering trick block, which cuts off the workaround iPhone owners have been using to get around AT&T’s official reluctance. If it makes it through to the official release, I’m not sure U.S. iPhone users will be in a huge rush to upgrade, especially if the rumors of a $55 official tethering plan prove true. AT&T’s official stance at this point is that those particular rumors are not true.

Some additional improvements about which few details are available are battery life improvements, and more access to video functions for developers, which hopefully brings us one step closer to “true” augmented reality capabilities.

Still included in Beta 2 are the Voice Control via Bluetooth and non-destructive video editing features first introduced in Beta 1, which came out June 30.

Mac OS X “Snow Leopard” Build 10A411

This appears to be yet another minor update on the road to the Snow Leopard GM candidate, with all the usual bug fixes, security enhancements and stability improvements associated with that kind of build. The last update did see some UI tweaks, but at this point no new feature additions should be forthcoming.

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• Mobile Q4: All Eyes Were on Android, 4G and the Rising Tablet Tide
• Report: A Mobile Video Market Overview
• In Q3, the Tablet and 4G Were the Big Stories