Thanks to Kostya, ffmpeg now supports the VC-1 codec, which is also used in Microsofts WMV9-format.

In the past, for Linux-users it was only possible to play those videos with win32codecs, which use proprietary windows-dlls and don't work on non-x86-platforms. With this improvement, one of the most common multimedia-formats unsupported by free software can now be played with all major free players (as ffmpeg is used by vlc, xine, mplayer, totem and many others).

Congrats to the ffmpeg-guys. The easiest way to get stuff playing is getting mplayer from svn (I used the mplayer-svn-ebuild from this Multimedia Overlay with some small modifications).

(via Breaking Eggs and making Omelettes)