Rumors about Nokia's unannounced "Ace" LTE Windows Phone have been building, and now the handset is all-but-official: The New York Times cites sources who say that Nokia plans to unveil the Lumia 900 on Monday at CES, and that it will be headed to AT&T in the US. We still don't have confirmation on specs, but if the rumors hold, we're looking at a 4.3-inch WVGA display, 512MB of RAM, and 8-megapixel camera, all running Windows Phone 7.5 Mango. We reached out to Microsoft for comment, and a company spokesperson had this to say:

Neither Microsoft nor Nokia have discussed or confirmed.

We're sure to hear more on the ground at CES, so stay tuned.