So the tbolt is pretty much it for single core, eh?
For single core phones, it looks to me like the tbolt might be its final, shining, hour. And if the unlocked bootloader rumor is true...(or at least I think I read that xda said it was as open as nexus/droid)
It would make sense for it to be unlocked. We've seen how much longer the og droid has lasted than expected because of the openness, it would be logical for the tbolt to continue to be competitive with dual core phones by being open to the dev community.