After waiting what felt like forever, compiz now works again for me with KDE 4.8. (That is to say, it works on Kubuntu 12.04 pangolin current build.) At least, one of the major bugs (this is the one I filed, after complaining about it here) is fixed, which makes the compiz/KDE combination usable again. I haven’t tested if some of the panels still do bizarre things like become permanent overlays on the screen, but I’ll get to those later.
In any case, I’m happy enough to be able to use KDE and compiz together again. You know, I think I’m starting to like Pangolin… and it’s still on the first alpha!