Speaking at QuakeCon, John Carmack warned that the capacity difference between DVD and Blu-Ray discs might force id to reduce the quality of its upcoming title, Rage.
According to Carmack, the uncompressed build of Rage encompasses a terrabyte of data. After compression, this data can be stored on a single Blu-Ray disc or 3 dual-layer DVDs.
Unfortunately for Xbox 360, the royalty fees for the third game disk are high enough to makes it an unfeasible solution. Carmack hopes that Microsoft would make a concession, but if they refuse, he'll have to cut back on the Xbox 360 version quality.
When asked for more details, Carmack explained that "hero shots" should look similar, but that Xbox 360 players might find a rock that is more blurry when exploring the periphery of Rage's world.