I finally made it out to a movie last night. School of Rock does indeed live up to all the praise critics have been heaping on it. It's got a formulaic plot that doesn't stick to the formula. So while you get something safe and comforting, it's fresh and hip at the same time.
Parents and teachers could take a lesson from Jack Black's character: The kids in the movie like and respect him because he asserts himself as an authority figure without ever condescending to them. The unncessary PG-13 rating might suggest otherwise, but this is really a family film. Black is hilarious, but the kids shine just as brightly as him. They're cute, they're funny, they're endearing, and they act like kids really act.
Is the movie realistic? Of course not. But we don't go to the movies for realism; we go for escapism. Beyond being funny, School of Rock is just plain fun.