Our buddy Phil Kollar of Game Informer (who was on the podcast recently) got a chance to talk to Jeff Kaplan about the World of Warcraft, and while Kaplan repeats a lot of what he's said before, the interview is worth a read for a look inside Blizzard's design process. What's probably most interesting is that it's very fluid and very dynamic -- just as much as we're arguing on this site and on the forums about how Blizzard should do things, they're also arguing and going back and forth behind the scenes.
He does talk specifically about cutscenes, saying that the Wrathgate scene was an experiment that paid off well, and we should expect some more of that kind of storytelling even as soon as in patch 3.3 (you may have seen it before if you're checking spoilers). And he does talk about raiding sizes and accessibility -- Blizzard has always wanted to do smaller raids, both for the feel of them and for the tuning, but it apparently took them a while to bring 40 down to 25 and then down to 10 correctly. Finally, he doesn't reveal anything about the new MMO, but he does say that singleplayer gaming will always have a place at Blizzard's core -- even when you're playing a multiplayer game, the singleplayer experience should still feel right. True enough, good interview.