It really does depend. I'll say it this way, I will, but not at full price. I bought DA2 for $20 on Amazon. I bought ME3 out of the gates, and I really like the game, though I don't know this fabled ending that is pissing everyone off since I haven't had time to play it. With DA:O, they kind of hit their epitome, and I don't see them bouncing back as long as they continue to change games all the time. I was mad at the changes made between ME1 and ME2. ME3 is like ME2, which is still a good game. I was a bit livid about the changing from DA:O to DA2 though. It's like waiting to see the sequel to a movie you love, but they changed the actors in it and now it's just bad.
I am the first guy to say that games should be judged on their own merit and not compared to predecessors, but c'mon. You can't change everything about a game when that everything is what made your previous iteration sell. Also, while TOR was fun, I don't think it was different enough from WoW to make the money worth it, that is why I canceled my subscription after the first month. The only thing different was the fully voice acted bit, but it's not 1994 anymore, "full talkie" isn't a draw to a game like it was back then. I have to say that it depends on the game. I might look at a new franchise from them in the future, but I'm not making any promises.