Well, I can't wait personally. I'm a big fan of his work in general, but Bowling for Columbine was excellent. I didn't agree with all of his conclusions, and I certainly think his politics are sketchy in places, but ultimately the film was still worth watching. I can say honestly that I recommend the pro-gun crowd to go watch it to - even if you hate Michael Moore from what you already know of him I think you'd appreciate the film on some level. He is far from being the typical American Liberal, from my reading of him anyway, so don't get too worked up about how much you disagree with him just yet...
And also, quite frankly, his stuff is hysterically funny in places. He presents awful topics in a way that the facts are still brought home to you, yet you find yourself laughing at the absurdity of it all. Thats his talent, IMO, he can really pinpoint the absolute ridiculousness of a situation!