I am still on the lookout for info on this, just got home and using good ol interweeb to see if this is true.
I see nothing about it anywhere, but the source comes from M$ itself, so leaves me pondering.
edit : just thought i would add his quote.
"you will not have to change discs to go around the map, it is only for the storyline"
Edited by xmod4u, 24 April 2008 - 02:47 AM.