Also the argument about 20% of games using the HDD is ridiculous IMO,
#1 - since PS2 has majority market share, outselling xbox over 4 to 1, all cross platform games had very little motiviation to make any use of the HDD, this is not proof that the HDD is useless, it's simply a result of the current marketplace.
#2 - the BEST games for xbox, the EXCLUSIVE games that set it apart from PS2 all used the HDD extensively, Halo1, Halo 2, KOTOR, Jade Empire, Forza
The AAA titles did use the HDD, so who cares what the final percentages are? The BEST games used it to make the games better and extract the most performance they could out of the hardware. These are the games that we bought XBOX's for, not the 80% of shit, cross platform ports.
At the very least it provides an unlimited swap file for developers to use, so they are not simply limited to 512MB of writeable memory. Hell, Halo 2 which is 2 years old uses 2 cache directories and stores WELL OVER A GIGABYTE of swap files, that's on a system with only 64MB of ram.
It offers flexibility more than anything, as well it opens the doors to many more PC ports and PC-based games, and also is essential for an entire super-genre of games(MMO's) from MMO-FPS to MMO-RPG here's an entire genre that needs a HDD.