They're mergeing back apparently. I never bothered with Beryl, I don't think it's in the standard Fedora repo's anyway.
Compiz comes pre-installed at the moment, though I think F 7 will use Beryl or compiz-quinn or whatever it's called these days.
I'm thinking of heading back to KDE once version 4 is out so it'll be interesting to see how KDE handles it all. Last time I tried about 9 months ago I ended up breaking KWM
this was before AIGLX etc though and you had t ocompile a bunch of stuff from the nightly CVS builds, imagine its calmed (and stabilized) a lot since then.