In an article hosted by by crave.cnet.com titled "Rockstar's mysterious PS3-exclusive game may only fit on a Blu-ray disc". An interesting quote is mentioned in the article. They are quoted saying
"Of course, if the game is as great as Rockstar says it is, we might not see it until 2009 or 2010. By then, any AAA PS3 game will be so massive in scope that it won't fit on a DVD, only a Blu-ray disc."
There is no official word confirming this. However it has been mentioned time and time again that future games will be massive. Could this be Sony's PS3+Blu-Ray combo showing face?