Eurogamer's review is up. Oli give it an 8/10. I'm sure fanboys will cry afoul, but his review makes perfect sense and I'm still planning to buy a PS3 for it.
Without going into spoilers he basically says that it's a very bloated game bursting with ideas, but not all of them good. The plot, he says, is a muddled confusing mess, but it's told with such style that you'll feel for the characters even if you don't quite understand everything that's going on. He also says the cutscenes drag on way too long and are boring at times. However, he says that there are a lot of surprises in store and some really brilliant ideas in the second half that you can tell he's just dying to talk about, but can't because then he'd spoil it for everyone.
I'm still as intrigued as ever though. His complaints ring true of MGS3 as well where the storytelling is really padded and unnecessarily long-winded, yet replaying the game, skipping all but my favorite cutscenes, has proven to be some of the finest moments in gaming I've had in the last several years. I expect MGS4 to also be a bit of a slow burner, but will have excellent replay value, so I'm still in for sure.