Well, it was only a matter of time until Guitar Hero jumped on the bandwagon and tried to imitate Rock Band. Personally. I hope Rock Band beats the pants off of GH only because in this fight between Vivendi/Blizzard/Activision and EA/MTV/Harmonix. I'm rooting for Harmonix who, even though they have made millions off Rock Band, they are definitely the underdog in this fight.
See more here. I think the Guitar Hero game will suck. But that's just me.