I'm considering that myself. I still have a 72 GB drive with nothing on it. I might attempt a 32-bit install on to it.
For the most part, I'm trying to run linux for x86_64 to stay ahead of the game, so to speak. I figure in the next couple of years most people will be moving to a 64 bit OS, and I'm one step ahead (sort of). Also, I wanted a SMP system, so it was Opterons or Xeons. I chose the Opterons because of amd64.
(Oh, and the big OpenGL app that I'd like to run is ut2k4 x86_64