RAZurrection on 17 April 2009
The only thing that'll be downgraded is the movie/audio quality which are all inherantly due to disc space.
But if it's like any other Xbox 360 multiplatform game, it'll have less aliasing, less slowdown, better 1080p scaling and superior texture quality.
Both aspects proving a point: Blu-ray holds more space then a DVD and Xbox 360 renders real-time graphics better than PS3.
