T-Mobile has the G2X, and is getting HTC Sensation in June...a 1.2ghz dual core beast that will be probably twice as fast as the TB. T-Mobiles internet speeds and coverage are not that great though.
ATT has the Atrix, which has a dual core, 1 gig of ram and a huge 1930maH battery. This blows any Verizon 4g phone out of the water. Att 4G speed can hit speeds of 6mbs, which is not too shabby, and their coverage isnt bad either. Verizon is either 1)trying to sell off their old technology to us, or 2) having problems with dual core/more ram and 4GLTE