It looks like one of Microsoft’s partners got a little too clever with the Christmas card this year, creating a holiday greeting whose central figure happens to be the unannounced Nokia Ace for AT&T. While that reveal by itself may not mean much, the fact that a front-facing camera is visible in this shot suggests that there may well be other differences between this Windows Phone-powered handset and the similar-looking Lumia 800 (besides the rumored addition of LTE).

Thanks to Paul Thurrott, we’ve learned that Ace will be one of three WP7-powered, LTE-capable phones to hit AT&T early next year, along with the HTC Radiant and Samsung Mandel. Ace will apparently be the second Windows Phone from Nokia to land stateside — after the Lumia 710 on T-Mobile — and should be the first to ship with Tango preloaded.

Update: Mr Thurrott is referring to this as the Lumia 900, meaning that non-US residents should probably take note as well.