Yes.
You install Quake2 to your PC, drop the Quake2x Xbox files into the same directory (preserving directory structure) and copy the whole mess to the root of a new DVD-R for the Xbox or into a folder on the Xbox's F:\games\ drive.
That's it.
Turn down the joystick sensitivity a bit in the game controls and rock and roll.
it's an amazing port. It's just about perfect.