Does anyone think that it's possible that having too many titles and too many songs available might run the risk of flaming out the enthusiasm for these kinds of games? Well, I guess Maxis does make a ton of money off of casual gamers buying Sims expansions/shovelware.
What I think the music industry should do is promote people buying music on CD by including a keycode inside the CD package to download the Guitar Hero or Rock Band versions of all of the songs on the album. It's a bit ridiculous to have to pay more than the full price of the album to just get the game versions of the songs. You should buy the album, and get the game songs free.