Save and Quit - "People participating in the Xbox 360 update program received their copy of Halo Reach in the mail today. Speculation over the new disc format has been everywhere since Microsoft made the announcement. According to an article by Just Push Start, hackers have dug into the new Halo Reach discs and found that they have a capacity of roughly 10GB. This cannot be possible as Microsoft is still using DVD-DL discs which can only hold 8.5GB."
Article provides proof of an 8.5GB disc.