I think they're using the same codebase for Linux, Solaris and BSD. As such, they share the release notes. The drivers for all systems are also always released the same day.
Originally Posted by zander
XvMC is not supported on Solaris.
Why is that? Technical reasons (i.e. kernel stuff) or no one tried if it even works yet? I'd figure that the MC code doesn't reference any platform specific stuff and interact mostly with the NVidia driver code only.