I can't say jack and/or shit until I see screens and see where the art is going, etc. That's the very first step for me. Fuck that up, you lose, and that's a huuuuge undertaking, even for an MMO which may potentially have more money to throw at such things. There's just so much uniqueness that you'll have to represent if you're going an RPG route, because you won't just be sitting in battlefields. This is going to be a massive undertaking requiring a fleshed out society that isn't just straight combat. I honestly don't know how they're going to pull it off, but it'll be interesting to see.
The one thing I'm happy about? THQ has it and not EA. I mourned the death of the fantasy Warhammer MMO being given to EA. Stupid fuckers.
Anyway, this is really something that we'll have to wait and see on I think. There's just no way to say "yay!" yet, but not necessarily any reason to get pissed. Also, I'm less annoyed with this going MMO because of the simple fact that the games are very much multiplayer experiences, so it's a natural progression. Of all the franchises to do this with, this one makes sense. Warcraft, while ultimately a success, didn't make sense in the same way.