According to the latest issue of PSW magazine, there are multiple cut scenes in Metal Gear Solid 4 that range in the 90-minute mark. Luckily, you can choose to either skip these scenes or pause them at anytime if you need a break from watching them.
I mean, the MGS series has always had a strong narrative and long cut scenes, but 90 minutes is stretching it. That’s some serious stuff. That’s as long as some movies. It's gonna be one of those things...you want to watch it all, because MGS is a cool story and everything, but gah...so long. I just want to play...but I have to watch or I'll miss out on major plot lines or cool video sequences. garg.