While debian-multimedia.org has gained a reputation of providing packages, which were desperately lacking in Debian, IMO this repository has turned into a major source of trouble and pissed users provoking flamewars in the recent past. There is still a number of remaining multimedia-related packages that we still lack in Debian, and pkg-multimedia is working on getting at least the most popular ones packaged and uploaded - help, as always, is of course very appreciated. [2]
The problem is that debian per se 1) is unusable for any serious multimedia usage. what are the version of VLC, ffmpeg, xbmc provided by debian?2) has long pretended they have the knowledge to make multimedia packages better than other
Instead of arguing you should be pleased someone makes debian useable for multimedia activities otherwise people will move to ubuntu where also multimedia packages are maintained via non official PPA
Have you heard of raspberrypi, cubox, spark, that are making the buzz. What is demoed on it: multimedia capabilities. Will debian be attractiive without multimedia packages: no.
In summary, I can only advise everyone against enabling that repository on any machine.
Crap: I've been using that for ages (running debian since 96) with experimental+unstable and it is rock solid. Maintainer also fixes issues and respond to bug report more correctly than some other official package maintainer.
--eric