Well, it's always easier to learn a second instrument if you have a firm grasp on basic music theory.
I hated playing the piano, but in retrospect, it's really helped me pick up the bass faster/better.
I think it took an iPhone for the other guys to get innovative like this. I really like this interface, though unfortunately it'll take more than that to dethrone the iPhone; though I don't think anyone can be sure until they've actually used it.