Got Ubuntu and Kubuntu 10.10 today, in both x86 and x64 versions. Picked up Kubuntu 10.10 for my PowerMac G4 as well.
Ubuntu 10.10 has a few improvements over 10.04, but not much. Namely theme enhancements, startup time, music player menu, etc. Don't care for it.
Kubuntu 10.10 I'm currently installing.
And can someone tell me what the Kubuntu live CD username and password is? I tried to boot from the live CD on my PowerMac G4, only it timed out and didn't log me in automatically.