64-bit *nix is cool, so is 32-bit.
I'm going to be running 64-bit *nix (and 64-bit vista) w/ the new computer, though I may occasionally install a temporary 32-bit system on the 64-bit computer.
Wireless is hit-and-miss with *nix. Which wireless card do you have? If there is not already a reverse-engineered wireless driver, you might consider the "ndis-wrapper", an app that lets you use most wireless cards within *nix.
BIOS updates - cool! I have a hunch the M3N-etc.etc. will have that automatic feature. That'll be cool.
I actually think I might be receiving my CPU as one of the last
shipments! lol . . . so I'll basically have to wait for everything to come in before I can start piecing it together. No biggy.