http://kotaku.com/392923/mgs4-has-90+minute-cutscenes

I'm going for three hours of gameplay at this point. :P

EDIT: The thing that ticks me off the most about this is that I'm a very busy person. What do I do if I'm only forty-five minutes through one of the one and a half hour cutscenes and I have to leave for the rest of the night? I can't just pause the cutscene because my brother or father will most likely want to play at some point. They better have the ability to watch any previously viewed cutscene at any time and be able to fast forward and rewind.

UPDATE: From a Gamepro writer:

"I've beat the game twice, and am the author of the forthcoming [GamePro] review," Shuman said. "Ninety-minute-long cinemas in MGS4 sounds like an exaggeration. Like the other MGS games, MGS4 definitely has a cinematic quality. And yes, some of the cut-scenes in the game are elaborate and occasionally lengthy. But not a one, to my recollection, even approaches 90 minutes.

"I think it's safe to say that the '90 minutes cinemas' claim is a pretty big exaggeration," he told GamePro News.

So, there you have it.