Summary:

Coincidence or design? Today came not one but two developments on the state of unlocked iPhone 4S devices: Apple (NSDQ: AAPL) will start to…

Siri on iPhone 4S
photo: Getty Images / Oli Scarff

Coincidence or design? Today came not one but two developments on the state of unlocked iPhone 4S devices: Apple (NSDQ: AAPL) will start to take orders for unlocked iPhone 4S devices just as Sprint (NYSE: S) has confirmed that it will lock all 4S’s that are sold on its network as of today.

The news comes in a week where Apple has had a few knocks: the stock has been in decline on reports of lower unit sales in the next quarter, and user disgruntlement over ongoing battery issues with the new version of iOS.

Apple’s unlocked device — now being pre-sold via its U.S. site, available in U.S. retail stores, and going on sale in the UK (and possibly other markets) as of 9PM UK time tonight — will let users replace the SIM in the device.

In the U.S. the unlocked 4S is selling for $649; prices in the UK have not yet been put on the site.

SIM replacements are not something users can normally do if a device is bought through a carrier under a two-year contract: that has been the most typical arrangement. Having an unlocked SIM not only means users can change the home network cards for low-cost, local SIMs when they travel abroad, but it also means that users could potentially migrate to other carriers if they opt to take contracts that are SIM-only and work on a rolling basis.

In both cases, it’s a more precarious position for carriers, who would have presumably leaned on Apple to delay sales of the unlocked version of the iPhone to give them a headstart in sales.

The unlocked devices now being sold by Apple will only work on GSM networks: the company points out devices sold for CDMA-based networks like Sprint’s and Verizon’s in the U.S. will be locked.

That was not always the case, at least for Sprint: when the device first debuted on that network in October (the network’s first foray into selling iPhones), it was sold unlocked. As of today, that will no longer be the case. According to MacRumors, it seems that devices bought through Sprint before today will remain unlocked — something that, if it had been more widely known by consumers, might have attracted a few more of them to Sprint in the opening month of sales.

This tango around unlocked devices could translate into a bump in iPhone sales — although with a pricetag significantly higher than the subsidized devices, and no evidence yet of widespread iPhone SIM-only plans in the U.S., it’s hard to believe that it will do so in all markets. SIM-only plans are significantly more common in markets like the UK.

What the news underscores, however, is how Apple is pushing the boat out in trying to offer consumers more choice on the devices.

The company is doing so at a time when it is fending off some negative publicity.

There are unconfirmed rumors that it is cutting shipment numbers for the current quarter, and users continue to complain about battery issues, even after installing an update to the new operating system, iOS5, that was supposed to be the root of the issue.

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