Which Android based phone should I get?

[Theo]

The next cell phone that I am going to get will have the android os. The problem is I don't know what to get. I am on T-Mobile (NYSE: DT) and have no plans to leave them. I like the Mytouch but not the cliq so much. Physical keyboards are not need for me. Another factor is the need for expansion. I heard rumors that the g1 wont be able to run android 2.0, so I want a phone that will be able to handle upgrades. I know of the Samsung Behold II but it doesnt get my fire burning. I know Sony is bringing out the Xperia X3 or X10 ( whatever its called) with android and its own UI. Much like the HTC Hero has the Sense UI the Xperia will have the Rachel UI and its looks awesome to me plus the rumored specs on the phone look top of the line. The problem is I don't think it will run on T-mobile 3G frequencies. So if the Xperia does work on tmobiles 3g network I'm getting it but if not what else can I get?

PLZ HELP! (My gf is gonna kill me)