Compiz is an evil dying hack
Often I said that Compiz was an evil hack as it was replacing the native and eventually well tested desktop windowmanager with a new code unstested and unstable. Now Compiz is at an important point of its life, and some decisions may make it become irrelevant in the future.
They plan to use C++, improve the plugin system, allow it to run without any opengl/composite, etc ... Theses are sensible move, however IMHO Compiz lost momentum and will soon became an irrelevant technology. The reasons ?