Well, I see that this is out. Downloaded the sucker (had Kubuntu on it before), and so far, so good. I did decide not to install GRUB the first time...whoops! I think I've done that once before...and forgot that it doesn't work well when there's no bootloader in the system. Haven't actually messed around with it too much, but I will shortly so I can fiddle around with the network settings. I should just get a DVD drive for this box...kinda annoying since it's my mega toy box.
Yeah, CentOS 5 is great. I'm running it on the newest incarnation of my home webserver (albiet without any GUI whatsoever), and it's pretty nice so far. I'm kinda surprised by the freshness of the packages, considering it's RHEL, and RHEL tends to be a little stale by the time they consider it ready for production use. Don't forget to add the DAG/RPMForge repository to take advantage of another several-thousand packages for CentOS/RHEL!
I seem to always come back to CentOS. It just works. Not as snappy on the boot up as Kubuntu, but it just doesn't give me trouble.