[stiborg]

I have all the files (music and videos) on NAS'en that I have connected
up to my Apple TV. I wonder if there is any way to automatically
download dvd covers? I know it works when the files are located on the ATV, but it does not work when im using NAS. Is there a way to fix that?

[Krieg]

Yes, XBMC will built the internal library. Provided you use proper names for the files.

[tyche]

You can do it yourself with the help of XBMC Companion

http://forum.xbmc.org/showthread.php?p=243321

Or you can change to Library mode and assign your Sources a default scrapper (part of the process when setting up a source) and let XBMC do it all for you.