I think I'll pick up the TMobile version this Thursday when it comes out. It's supposed to be a pretty nice and fast phone. It has a 1GHZ Hummingbird processor with a gpu that is 3x faster than any other phone out. It also has 512 RAM.
The Tmobile one has no front facing camera or flash like some of the other carriers but it does have 16gb internal memory and another 2gb SD Card included. The 4" Super AMOLED screen is supposed to be very nice. Also comes with Kindle, Sims game and Avatar in HD (on the 2gb sd card I heard) and Android 2.1. I have read that they are going to be putting 2.2 on it but we will see.