O conteúdo do pacote foi movido para compiz-plugins
e o pacote fictício foi removido em 12.10.
Este foi o estado em 12.04:
$ aptitude show compiz-fusion-plugins-extra
Package: compiz-fusion-plugins-extra
[...]
Depends: compiz-plugins-extra
Description: transitional dummy package.
This package ensures a clean upgrade path, and can be safely removed after the
upgrade.
Homepage: http://www.compiz.org/
$ aptitude show compiz-plugins-extra
Package: compiz-plugins-extra
[...]
Description: Collection of extra plugins from OpenCompositing for Compiz
The OpenCompositing Project brings 3D desktop visual effects that improve
usability of the X Window System and provide increased productivity.
This package contains extra plugins and themes contributed by the community
giving a rich desktop experience.
Homepage: http://www.compiz.org/
Note que compiz-plugins-extra
agora é um pacote fictício em 12,10 também.