Everyone knows the Xbox 360 does not currently have any support for what are considered the next generation storage standards like Blu-Ray and HD-DVD, but you may not have to worry, as it looks like most titles will fit on the 9 gigs of space that the disc has.
Most people thought that the Xbox 360 was not going to have enough storage space, but it actually looks like the original Xbox had too much. Currently, titles being released for the Xbox 360, do not even take up one half of the total storage space on the discs. Even if game sizes continue to grow by leaps and bounds as they have in the last four years, the DVD-9 disc will only be 87% used up in the year 2010 thanks to authors being able to cram more information in less disc than they could in previous technology.
I think a little common sense is needed in thinking about game sizes. When you install a game on your computer, does it usually take up more than a few gigabytes? How many games do you know of that pass the 10 gigabyte mark? Most games I have played on the computer are still around the two gigabyte mark. I have every confidence that I can be provided with some wiked gaming over the next four or so years on the DVD-9 disc standard, even if the developers have to use a gigabyte or two of the hard drive space to make it work.