I've been peeking at the KDE4 beta articles for awhile now, so you could say I'm interested in what's going on. But, I didn't want to install to see what it was really all about. Well, you don't have to...
They just released beta4. One of the articles I was reading had a link to a Debian liveCD...
http://cdimage.debian.org/cdimage/unofficial/misc/
They have i386 and amd64 versions. The login for the liveCD is "user" and "live".
I've also been playing with VirtualBox recently. It can boot an ISO image in a virtual machine, so there's no need to burn a disc or reboot your computer.
I haven't played with it very long, yet, so I don't have much to say about it other than, it is pretty.