I think if it was any other MMO then it would be quite successful, though never coming remotely close to rivalling WoW. Sadly it's not any other MMO, it's TOR - the single most hyped new MMO since... well, since WoW, but that kind of lightning just doesn't strike twice.
I have no doubt that EA have VERY high expectations for their 200 million dollar mega project, though they certainly won't tempt fate by admitting it. Given their obsessive pursuit of CoD with Battlefield 3, EA simply must be eyeing up the 800lb gorilla of the MMO world. And that never ends well.
Too singleplayer focused to appeal to the MMO die hards, and too MMO to appeal to a big part of Bioware's fanbase. I expect it to have a huge launch, and six months from now I expect to read about server mergers, followed six months later by it being relaunched as a F2P title. Whether it's good, bad or indifferent is besides the point. At this stage TOR simply cannot live up to the hype that's built up around it.
I'm not saying it will be a bad game. I expect it to be slick and enjoyable, but once the hype wears off I expect it to be viewed as 'a good game', but that's all.