It's been brought up in the forums about the state of upstream Compiz developments. Some Phoronix readers go as far as calling upstream Compiz being dead. Those comments were largely based upon outstanding Compiz bugs, the lack of Compiz releases, and the lead developer apologizing for the "failure" of the Compiz project on his blog. In his blog posting from December, Sam Spilsbury apologized for the lack of new direction, lack of development, and not any increased stability for the project.
Besides Fedora, other distributions dropping Compiz include Gentoo and openSUSE, among others. The main "customer" of Compiz is really just left to Ubuntu with their Unity desktop, as the GNOME 3.x Shell is set with its Mutter compositing window manager and the KDE4 desktop is being quite pleasant for most users with KWin.
In terms of the Compiz code itself, the Compiz code-base itself on Launchpad.net is still being actively developed. The last commit to the Compiz Bazaar repository happened just days ago, but it's still far from hitting the Compiz 1.0 release.
Compiz is not as vibrant as it once was years ago, but simply due to the support by Canonical/Ubuntu, this original compositing window manager is still around.