I don't get the concept of Lego Rock Band. So the animation is Lego. Everything else is the same, right? You can't Lego-ize a song. Unless you're getting songs on it that you can't get otherwise (like Rock Band AC/DC), which hopefully you can also download to your console, what's the point?
It's aimed at a younger audience - all the songs will be "kid- and family-friendly', supposedly.