The DLNA functionality is really a nice to have but...
The DLNA Media Server is really too light.
For me, the Synology Media Server must be like that:
- Must be compatible with branded TV like Sony, Samsung, LG ... Media Centers (like windows MCE or open source), XBOX 360, PS3, digital frames, mobile devices.
- add or remove directories from the synology HDD but also (why not) directories on other sources like Windows PC or Mac.
- transcoding divx,xvid,mkv etc..
- include subtitles files like .str or mkv subtitles directly in the video streaming
- Streaming videos in HD (1080) to TV or XBOX360 or PS3.
For example, you can take a look @ EMTEC movie cubes.
I have found also a really good DLNA server "PS3 Media Center" with all this features ....
( I love my synology )