I played through this over the long labor day weekend.
Always been a fan of the metal gear games. The story is really convoluted, but still miles above most video game stories. The voice acting is also excellent for the most part.
The production values on this game are the highest I have ever seen. From the music to the graphics everything is top notch. They really flex the muscle of the PS3 on this one. The cut scenes are not pre-rendered, but look almost as good as if they were. The facial animations, attention to detail, etc. are without equal in video games. For example, during most of the cut scenes you can look around, change your view, zoom in, etc. It's almost like Kojima is daring you to find a mistake or something that doesn't look good.
That being said, I was slightly disappointed with the first 2 missions. They felt very similar to me. But at the end of Act 2 and continuting into Act 3 and 4, the story becomes Epic, including some very intense action sequences and cut scenes. Mission 4 esp. is fan service galore, returning to the scene of the first Metal Gear Solid game (including an amusing "dream sequence"). I won't spoil anything, but the end of the Act 4 is especially cool.
That being said, I really would like to see Kojima tackle something else. He is obviously trying to change the way we think about video games, but I still feel the story is too complicated and silly. I don't mind the extended cut scenes so much, but a lot of the ones in this game are filling in back story which just consists of someone talking over a fairly basic graphical display.