The Old Republic is "the fastest growing subscription MMO in history," has 1.7 million subscribers
EA just held their quarterly earnings call and released some juicy factoids about TOR's launch during it. Specifically, over 2 million copies of the game has been sold and 85% of players have subscribed or are still in their trial period (for a total of 1.7 million "active subscribers"). And those gamers are getting their money's worth: the average session time in the first month was FOUR HOURS, and over 1 million players were logged in simultaneously at one point.
In the Q&A portion, EA addressed concerns about the game's profitability by saying, "At 500,000 subscribers, we'd break even. At a million, we'd be making a profit but nothing worth writing home about. As it scales up from there, we're talking about a nice profit. At this point with the successful launch, we can take the worst case scenarios off the table."
You can read more long-form quotes here.