Owners of Nokia's Lumia 710 who expected an update to Windows Phone 7.8 are out of luck.
The phone's sole U.S. carrier, T-Mobile, confirmed the news in a statement sent to CNET today:
At this time, the Nokia Lumia 710 will not receive the Windows Phone 7.8 software update. T-Mobile is committed to enhancing customers' experience with our devices, including providing upgrades to the latest operating systems, and T-Mobile aims to deliver software upgrades when it will provide a better experience for our customers. We'll share additional information on upgrades for the Nokia Lumia 710 when they are available.
T-Mobile didn't reveal any reason why the Lumia 710 is off the update list or if the decision is final. The statement used the phrase "at this time," dangling a carrot suggesting the update may arrive in the future.
A T-Mobile representative also told CNET that the carrier is "testing and actively working with device manufacturers to ensure that eligible devices are upgraded." The rep added that T-Mobile has "not shared exact timing for additional updates and will communicate further details as they become available."
So at the very least, Lumia 710 owners are in a state of update limbo.
For now, this leaves the Lumia 710 stuck at Windows Phone 7.5 since an upgrade to Windows Phone 8 isn't possible for older Windows Phone devices.
Microsoft designed Windows Phone 7.8 for those older devices to offer certain features available only in Windows Phone 8. The company revealed last November that the update would begin rolling out for a host of phones early this year. Other Nokia Lumia smartphones have already started to receive Windows 7.8.
Nokia revealed a week ago that the update had kicked off for the Lumia 510, 610, 800, and 900. The company did include the 710 on the list as well. But ultimately, such updates are driven by the carrier, not by the manufacturer. Nokia even said that Windows Phone 7.8 would roll out to "owners with an unlocked phone or operator approved software during February."
Adventuresome Lumia 710 users can manually update to Windows Phone 7.8 via a hack posted on the XDA Developers forum. But those who try will want to proceed cautiously.
Update, 2 p.m. PT: Adds comments from T-Mobile.