This is interesting from Rolling Stone:
"As album sales soften and the industry turns to alternate ways to get music to fans, the battle between the big music video games has become increasingly heated, and new sales figures indicate The Beatles: Rock Band has a bit of an edge on Guitar Hero 5.
The Beatles: Rock Band sold 595,000 copies following its September 9th release, while GH5 moved 499,000 units since it hit stores on September 1st. In all, both games help fuel a revenue increase of 72 percent for music video games compared to September 2008."
It seems that more people pretend to play guitar than actually take the time to learn how. I think, though, that it does get get some interested in taking it further.