I don't get why now that HD-DVD is dead that Microsoft doesn't sign on for HD-VMD. It uses the same laser and has a potential size of up to 100GB.(10GB up to 10 possible currently 20 theoretical max) That and they don't increase the cost by much at all. While 10GB a layer is not as much as HD-DVD or Blu-ray it's a good deal more than DVD-9.
I'd say Blu-rays storage will show later in textures and music (it has in music already but uncompressed music is mostly a waste there's some good compression methods with loss that is not noticeable by the human ear.) the extra content is very minimal amount of space and honestly I think they could have fit it on the DVD if they wanted they just didn't have it ready and saw an opportunity to get some extra cash from live and then later via PS3 by offering it "free" on a brand new disc that'll probably be released at 50-60$
Having said that, it's a decent game but I wouldn't pay more than 40$ for it which I didn't(yay e-bay)











