As long its actually involving the singing, dancing, n concert.. this kind of anime is fine for me.
And I think people should not worry this is the new "thing" in anime, because this kind of anime is hard to pull. Its need big budget and most likely established franchise to back it up (Im@s, AKB48, Maybe they gonna try make legit Vocaloid anime next time) and actually involving thing that's rare in anime : animation.
