I have my Thunderbolt, and because (1) my budget won't support it, (2) my TB has had none of the bad issues we've read about, and (3) I am in a 2 year contract, the next several 4G phones are only a curiosity.
About the only thing that would make me go for a very early upgrade would be a rugged Casio 4G Android. Maybe.
I also had an interesting conversation today with a VZW employee on a 4G deployment for some work computers. According to him, LTE uses two antennas, and I can understand how getting all this stuff crammed into a phone makes for difficult engineering. The site deployment is probably very standardized; the phone layout less so.
Doesn't mean I would not prefer the USB port had been put somewhere else on the Thunderbolt.