I love subsonic, but I use banshee (in ubuntu) to organize my music, which I then play on my android phone via subsonic.
Many media players (rhythmbox / banshee are both very common for ubuntu) store their cover art in a single folder, and link to it using a mysqlite database. When using these media players along with subsonic, or migrating a collection from them to subsonic, it would be nice if subsonic could read the database so I wouldn't have to find coverart twice. (adding the album in banshee, finding coverart using built in tools, symlinking / copying cover art to folder.jpg)
Subsonic is awesome! I'm going to donate again!