I fully believe fan created guitar TABs are fair use. Someone might try to argue that the equivalent is someone going to see a play over and over and providing the transcript of the play on the internet. I would even fully entertain the argument that even that is fair use. The music publishing industry has in the past year or so really cracked down on sites that provided guitar TABs. I was (and still am) incensed by this. How is someone transcribing some chords considered copyrighted? Hell, the same set of chords can be applied to a huge percentage of music out there. If U2 or Journey used the same chord progression that say the Beatles used, are they guilty of copyright infringement? Of course not!
Well, in a back-handed slap, they have graciously allowed a site to return as long as the publishers get a percentage of the advertising revenue. I would almost call this extortion. I am so surprised that the bands themselves haven't spoke up about this. Why wouldn't a band want their fans to pour over their material to spread the work further to others? Its basically a version of free marketing.
Even Jon Stewart and Lorne Michaels have come out criticizing Viacom and NBC respectively on their stance towards YouTube. Why wouldn't you want fans spreading the buzz? It's really the definition of viral marketing. I understand you don't want people putting the entire show online, but why not allow clips to wet people's appetite to watch the real show?
At some point I'm hoping someone wises up and we get a serious attempt at a consumer bill of rights. I know there have already been some feeble attempts in Congress, but I think the publishing groups like RIAA and MPAA have way too much influence over the process to allow such a novel and great idea to succeed.