Well, it ain't perfect this technology, eh?
Got mine working with a combination of old fashioned ways of installing what I already know is needed and using some of the automatic one-click Community stuff.
Do some searching for some older and newer guides and you'll find your path to multimedia nirvana on OpenSUSE 10.3 as well!
Essentially, I got the repos (most) installed from the Community Repository section of YaST Software. Instead of using the opensuse-community.org/Multimedia one-click thing as I had tried (and didn't really like the choices) on RC1, I just installed the stuff I wanted through YaST Software Management, uninstalling totem-plugin, choosing to keep Gnome Multimedia and to ignore this time, installing mplayer and w32codecs-all, upgrading everything from the Packman repo (which replaces Totem with totem-xine), making sure realplayer, flash, java6-sunplugin (removes java 5, say keep Gnome thing, ignore this time), trash java5-sun, install java6-sun are installed. Install all except the 2 weird libxine1 things and the gstreamer010-plugins-good-extra, gstreamer010-plugins-bad, and gstreamer010-plugins-ugly and the ffmpeg one, choose to have YaST include all architectures and allow, ffmpeg, make sure lame and mad, k3b-codecs, transcode, normalize, k9copy are installed. Install libdvdcss2 (not libdvdcss which the vlc repo offers), logout and in, install acroread, totem-browser-plugin. Go into File Manager superduper user mode and delete all the libtotem-complex-plugin files from /usr/lib/browser-plugins and /usr/lib/Firefox/Plugins (lets RealPlayer handle its files). Check gstreamer stuff in YaST and see that all of them are from Packman. Check that libquicktime (doesn't need to be from Packman, SUSE version includes everything), xvid stuff is installed (should be).
Then open your players and have Konqueror options plugins search for new plugins. Start up Firefox and everything should work.
Not so one-click, eh? But still not too hard. You wanna rip and encode mp3? Do that instead of Fluendo one-click. Also, you'll need to go into Amarok options and select the xine engine.