I know that KDE is working on a program allowing it to be run on Windows. Is it any good, should I wait, or should I look elsewhere?
I did try it a few months back. It is unstable and I was not impressed at all. Anyways, I was just checking it out on a personal interest perspective. So, I suggest to give it a miss.
Try it on Virtualbox or on VMware player, or make backup of your system for accidental crash after installing KDE environment
Since it is not considered a stable release, you should hold off on it unless you have an environment that you don't mind rebuilding if something goes drastically wrong. This applies to any software that is in beta or is not considered a stable release.
I don't see any reason to install KDE in Windows, windows default desktop is good already, why find an alternatives. If you really want to try KDE might as well install Linux, try Kubuntu: http://www.kubuntu.org.