I just read this article by Rob Walker about Guitar Hero from the New York Times with some interest.
Since Guitar Hero III came out reviewers have speculated that playing might improve your axe skills or give you an advantage if you were to take up the instrument. The consensus seems to be that it doesn't, but I'm not so sure.
The little plastic buttons on a Guitar Hero controller certainly bear no relation to the demands of fretting, but the need for spot on timing is universal.
If you have ever listened to a beginner play guitar the first thing you notice is that they speed up on the easy bits and slow down on the trickier sections. This is the bane of guitar teachers lives and is the reason they bug you to practice with a metronome. Once you start playing with a drummer you suddenly discover that you have to start marching to the beat of another and your kick ass riffs suddenly start sounding a little sloppy. I know plenty of people who can wail on a guitar, but dry up and blow away when faced with recording to a click track.
In an example from my own life. I've been playing guitar for about 13 years (at one point for about four hours a day) but a few years back I was getting frustrated with my playing and needed a change so I started playing drums in a band learning as I went. Gradually my guitar playing slipped and I realized that my Strat had been sitting unplayed in its case for 3 months. When I dug it out something strange had happened. My technique had gone to shit and I found I got cramp after a few minutes, but my phrasing had come on in leaps and bounds and I had made the breakthrough that made me interested in playing the guitar again.
So do I think that Guitar Hero III could make you a better guitarist?
If you are a beginner, or your phrasing gives you grief then I think it can only have a positive effect.
If you are wondering what all this Guitar Hero fuss is about then I suggest you try out Frets On Fire. It's a freeware game which you play holding the keyboard like a guitar and you can get it here .