This morning, T-Mobile sent out the press release officially announcing the T-Mobile G2. The release mentioned that the phone would be available for pre-order in limited quantites for existing T-Mobile customers later this month - but that doesn't quite jibe with the fact that Best Buy's pre-sale begins tomorrow for a very reasonable $200 (with 2 year contract, obviously). They even mention an official release date: October 6.
The specs are in the announcement link and picture above, but in case you're too lazy to read, here's a brief rehash:
800 MHz CPU (new Snapdragon architecture)
3.7" 480x800 screen
Slide-out four row QWERTY keyboard
Personally, I'm just waiting to see how that new Snapdragon CPU stacks up to its higher-clocked siblings, and how well it overclocks.