To a certain extent, playing an MMO is all about improving your character. The games are addicting because you're always working towards that next reward that's just "oh so close". If you want a storyline, you need to be playing a single player RPG where you [and your party] are the centerpiece and the savior(s) of that RPG universe. 10,000,000 people can't all be "The Hero". Another huge part of an MMO is the "epeen" factor, which is just a way for people to feed their ego to an extent that would be completely impossible in their real lives.
Bioware has never failed with a game, but I really worry they might not do very well with The Old Republic. I really hope I'm wrong.
"That's the reason my FFL team name is TrentGreenLeadBlock. When you see this mother****er coming around the corner on a block, put your children to bed and batten down the hatch on your girl's snatch, because the same power that destroys defenders can scar the minds of the youth and simultaneously impregnate any woman within sight, live or on television."