Today at Gamefest 2007, 1UP is reporting that Microsoft will allow MMO titles to require a hard drive. They are asking that companies request a size requirement right out. If the requirement goes up later, Microsoft is looking to offer ways to have a "degraded" experience for some users.
"We can't guess how much space you're going to need for your updates, and, if anything's going to keep you from expanding indefinitely, it won't be us, as much as market forces," said Ian Lewis, software design engineer at Microsoft. "Feel free to require 30GB for your game; that's just going to make your potential audience a lot smaller."
Silver Xbox Live accounts can also access MMOs without a Gold subscription. All of the details are still being worked out, however, with the final guidelines looking to come out in first half 2008.
