It looks like the PR1.2 update for the N9 is starting to get rolled out now, so your favourite MediaServer implementation will reach your phone soon.
A short hint if you’re eager to try it and you don’t see any files shared: For complicated and mostly non-technical reasons the device needs to assign so-called DLNA media profiles to images and media files. To start this, the device needs to go into idle mode once, so just let it rest for a while and all media created on the device should be available after that. This is a one-shot thing after the update, any files added afterwards will be fine.