@FusionAddict and Mr. Sinistar:
Well, I was thinking Kosinski could have asked Daft Punk for a demo before being formally commissioned to the project, and the music in the trailer is the result.
Sure, I could be wrong. Just thinking that perhaps Daft Punk cranked out that music very quickly, before really having a chance to sit down and think about what they wanted to do.
Something else I was pondering, is whether the theme from Flynn's Arcade sounds like a reworked, slowed down version of the Solar Sailer theme from the TRON Soundtrack with a driving beat to it.