Carmack says Blu-Ray Offers A Better Rage

In an interview during QuakeCon; John Carmack stated, their upcoming title Rage would look and sound better on PlayStation 3, compared to Xbox 360 counterpart, not due to systems extra horsepower but rather related to storage space issues. Blu-Ray disc offered in PS3's can hold the entire game without any need for compression, but that is not the case with 360, due to their use of standard DVDs. Carmack says their intention was to make Rage, a 3-Disc game for 360, but Microsoft royalty fees makes it rather unprofitable...I guess downloading 10-15GB of the game through internet would be one solution to it, but as it looks for now, 360 owners might lose quality on textures and sound when the game comes out, because Id would have to compress 3 disc worth stuff into 2 discs.
My personal thought is; Microsoft would better upgrade to Blu-Ray on all 360's, because as time goes by, we will start seeing more games requiring that extra space Blu-Ray provides for developers.