Although I don't play it anymore, Rift is still doing well (for ITSELF, not compared to WoW) with a subscription. F2P, although having a shaky start (pay to win/necessary to buy to progress), has shown itself to be a viable, consumer-friendly method if done right. League of Legends, Tribes Ascend, LotRO, etc, are all good examples, IMO, whether you like the game itself or not.
GW2 is going to do extremely well, and it's going to put pressure on all MMOs that charge a monthly fee to make that fee extremely worthwhile for consumers to pay. Most likely it's going to force the hand of Rift (a quality MMO) to possibly think of F2P also.
I played the SWTOR beta and it was pretty obvious it was going to flop, at least in regards to how much they spent on it vs. how good it was/how many people would keep subscribing. Hated the plastic characters/armor.