most of my guild are gonna be transferring from WoW to SW:tor and we're still undecided about faction, but at the minute we have a republic guild set up - so in the assumption that we follow through with a republic guild i'll be going either:
jedi knight tank
jedi consular tank
or trooper ranged tank
i think i may be rolling a jedi consular (or sith equivalent) to start with, as i love the idea of tanking with a double-bladed lightsaber, then i'll be rolling a trooper for some ranged tanking as that looks.... different, then finally, i'll level a jedi - will have to see how they all play out before making a final decision on which i want to raid on.
although with something like 200hours playtime needed to reach max level, i'll hopefully figure out which i want to play a long way beforehand, thinking i might level each up to about level 15/20 and then make a decision of which one to make my "main"
edit: oh and YAY for our own SW:TOR forum! - thanks boub!