You could also install bianca kde and do a dist-upgrade. You might miss out on a few things, but otherwise it should be fine. I can't remember where I found it, but there is a how-to in the forums regarding this issue - perhaps even a sticky. Or, you could just wait until the cassandra edition comes out. In fact, that's what I am doing. In the interim, I am using cassandra gnome and am pleasantly surprised at how much I like it (especially since I have had problems with the kde sound system and lots of app crashes). Good luck.