Back when I was ignorantly sitting in WoW all day, I believed like many of these quitters that other MMOs just sucked. But over the years I've gained more insight into the development of both games and MMOs, plus participated in a few betas (though IDK if I can call my purchase of beta minecraft testing ).
The Old Republic is the first MMO made by Bioware. And for their first MMO it's not bad. It has bugs, it's unpolished, it's missing a few features. But I see the devs not cowering, rather fixing things. There's a fix coming soon for the Ilum camping issue, a LF system down the pipe, and Legacy is being implemented.
If Bioware can keep up the morale in the studio, I can see this being one of those games that defies expectations and does become successful. No, not a WoW killer, but I don't think 4 million subscribers it out of the question at all once the game is polished.
Blizzard made WoW in about 3-4 years. Bioware made ToR in 5. Not too different in timelines. And really, ToR had more launch features than WoW ever did.