Maybe they talked about this in the stream and I missed it, but this is something pretty big concerning the new Dashboard and its features:

From Major Nelson's site:

· Play from hard drive. Copy your games from the game disc and play directly from the hard drive. Not only will the drive not spin, but load times are quicker, as well. Of course, you will still need the disc in the tray to prove you own the game.
Optional installs. Yadda yadda faster loading, will probably also help considerably with the overheating of the system. Coupled with how they're releasing (or is it 'released') the 60GB 360 for $350, looks like they'll be pushing for this.









Also, Bungie.net has a countdown.
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