Blizzard's Jeff Kaplan on Warcraft's Past And Future on GameInformer.com is an interview that goes into detail about World of Warcraft with Jeff Kaplan, designer on Blizzard's MMORPG. The conversation covers many areas, including a bit highlighted on IncGamers (thanks Ant) saying that the version 3.3 patch will include their next experiments with in-game cutscenes:

Cutscenes will always be something that we use sparingly, yes. We never want to interrupt gameplay too frequently or for too long of a period of time. The Wrathgate cutscene was a big experiment for us. It was our first foray into in-game cutscenes in World of Warcraft. I don’t think we’ve fully refined how we want cutscenes to work with future World of Warcraft content.

We debate like crazy. We debate the length, we debate the frequency, and we have a lot of theories, but Blizzard is a really iterative development house. I think what’s going to have to happen is that you’ll see more cutscenes come into the game for us to really refine our strategy with them. We definitely have an eye toward more cutscenes, but at the same time, we don’t want to become just a cutscene game.

Even before Cataclysm, in patch 3.3, there’s going to be a really exciting cutscene moment that’s going to be our next experiment with that.