Compiz is on the list of packages that are set to be "retired" from Fedora. There's a whole list of the packages set to be retired from Fedora 17 in this mailing list message.
The package retiring comes from packages that no longer build against the current state of Fedora and/or are orphaned by meaning they no longer have an appropriate (active) package maintainer. All of the Compiz packages have been orphaned (meaning there's no maintainer) and so as such they are likely to be stripped away in the next week if no one picks them up. The retirement list for Fedora 17 has been floating around since last month and no one's been interested in Compiz yet.
Granted, this isn't too much of a big deal since the default Fedora 17 desktop will be the GNOME 3.4 Shell, which uses Mutter as its compositing window manager. There's no other desktop environment in Fedora 17 that's dependent upon Compiz, unless the Unity desktop discussions for Fedora actually materialize. The Unity desktop is the last big user of Compiz, with the compositing window manager project itself still being developmentally challenged and as of yet has been unable to hit the 1.0 release milestone. There's also the MATE Desktop (GNOME 2 Fork) as a potential Compiz user, but that hasn't been picked up by Fedora yet and so far has seen limited new development.