Most online music stores get their music data (artist bios, band associations, genres, and album reviews) from the same place: the AllMusicGuide, which started out as a book, but now spans a truly massive amount of music having been a website since 1995. They're adding to it all the time; just yesterday, I helped one of their writers track down some friends of mine to get promo copies of their debut album (AllMusic doesn't do promo copies), so I know they're actively adding content.
The recently-launched WikiMusicGuide looks like it wants to be the Freedb to AllMusic's Gracenote. Anyone can create or edit the band bios, album descriptions, similar artists, trivia, and external links on the site, and all work is released under the Creative Commons' ShareAlike license, meaning that device manufacturers and online music sites will be able to use the information for free, should it become useful enough (the site is only three days old).
It's an interesting idea, but only time will tell whether it'll take off. If you like the odds, start adding info – who knows, maybe your artist bios will end up in the Zune store someday.
