Today we eventually got the vorbis parser in libnemesi in a better shape, it seems to work fine enough to let us hammer some bugs in the MPlayer integration tomorrow we'll try to get aac support in and then decide if the api is fine as is or if we should try to improve it a bit more before a complete release (ridden for sure of more bugs that we'd like to, but it's always like that)
So if you like vorbis or you are interested in trying it over rtp please fetch the latest sources ^^