A little bit too much Live-dependent, but still a must have for music lovers.
I just wish there were more gameplay options for those of us who have no access to Xbox Live. There should be some kind of offline scoreboard, so one could compare his scores to his friends' and family (or even himself). I REALLY miss a feature like that. After finishing the band tour, your only options outside of Live are quickplay and training. I also wish there weren't so many live-related achievements.
Harmonix boasts about the game having 80+ songs, but after a hundred hours of play, you get pretty much tired of those ones. Good thing there are expansion packs and, for Live users, an online music store with inexpensive songs (there are actually 20 or so that can be downloaded for free).
I see it as a must have for anyone who likes this kind of game.