Today, I upgraded one of our Ubuntu boxes at our lab from Feisty to Gutsy. I was expecting to see compiz-fusion in its full glory. But unfortunately, that was not to be.
Although the upgrade went smoothly. But after the upgrade (followed by a reboot), I found compiz was not enabled by default. So, I manually tried to enable compiz (System -> Preferences -> Appearence -> Visual Effects). But it failed with the message "Blacklisted PCIID '8086:29a2' found". Turns out that the Intel i965 Video chipset used by our Dell Dimension has been blacklisted by Compiz in Gutsy. Fortunately, fixing this was easy. A little google search turned up the workround.
Just put the line "SKIP_CHECKS=yes" in ~/.config/compiz/compiz-manager and then tried again. This time it succeeded. (The file 'compiz-manager' and the directory 'compiz' was not there. So I had to create it first).
Now, compiz is working! From what I read somewhere on the web, I might have problems playing videos with compiz enabled on this machine. But I also read that there is probably a compiz-fusion plugin to solve that problem too (didn't try it yet though)