Having VLC acting as a DAAP/UPnP server would be quite cool. It would probably make a lot of sense as well due to the number of media formats it supports and its transcoding abilities.
This probably will have to be implemented as an interface module due to the fact that it needs to export the current playlist to clients. There will also need to be a stream output component but that part probably won't require much work....
Actually the whole thing would probably look like another VLM... altough probably substantially simpler... hmmm
This needs more thoughts anyway.