Linux Mint 12 was a phenomenal release and the lead developer wanted to continue his work by working on KDE-based Linux Mint release. He has just released the Release Candidate version for the upcoming Linux Mint 12 KDE which is based on Kubuntu 11.10, but with the latest KDE version available, KDE 4.7.4.
This version comes as a Hybrid ISO, which means you can simply use the "dd" command or a graphical frontend to make a bootable USB stick with no efforts which acts exactly like a liveDVD.
There are some known issues on this release which are mentioned on the release notes. Please read them to know the solution for those problems.