If you believe all the rumors that've been floating around, Motorola's hard at work on a new Nexus smartphone (codenamed "Shamu") with a 6-inch screen. Well, guess what just popped in to make an appearance at the FCC? You nailed it: a Motorola smartphone with a 6-inch screen, and with support for AT&T and T-Mobile's frequency bands to boot. As always, Motorola representatives have petitioned the FCC to keep all the really juicy bits confidential, so it's far from a definitive nail in the Nexus rumor coffin. Still, it's yet another piece of evidence that points to Motorola's role in crafting Google's latest Nexus smartphone. Why, just the other day it was spotted in Geekbench's test database putting up some particularly strong numbers. The specifics of the radio should mean the GSM model comes first (which is really nothing new), but Verizon Wireless may be getting in on the fun come launch time, too. Bear in mind, those reports and appearance came to light within the past week -- pretty soon (and if we're lucky) there won't be anything left to leak.