8310 and 8320? That third digit makes all the difference, and the Pearl's no different. Like the 8320, the 8120 adds WiFi -- a boon for UMA, and likely for T-Mobile's Hotspot @Home -- and also adds a number of improvements seen in the CDMA Pearl that's been floating around as of late, like a 3.5mm headphone jack and external microSD slot. These rumors have all been in the pipe for some time, and as is so often the case, the FCC has been more than happy to confirm all of 'em with the outing of the 8120 via filed documentation. The model in the FCC's clutches isn't carrier-branded, but we figure it's a pretty safe assumption that this sucker's headed to T-Mobile, no?