Agreed. I only think that they're making this game based on Raiden is because it's going to be cross platformed. The fact that the 360 discs can't really hold too much info, they're probably not going balls out on it. I'm pretty sure, they're saving all the juice for a future release of Metal Gear w/snake (or Big Boss). I just don't see too much epicness coming from tis particular game. I could be wrong, but we all have seen how big MGS4 was, and that was due to the fact that a Blu Ray disc has a larger memory, therefore making it longer, and over all more epic.
Yeah, sure, make the argument that the 360 can make multiple discs, but I'm sure they don't want to go that route.