Yeah, I like Rob and Ozzy and I remember Lita, but Jack Black? Any trailer that's all cut scenes is a bit of a warning, isn't it? "We had no good gameplay to show you, so please accept these cut scenes instead."
I like Brutal Legend, it's one of those 3d adventure games where you run around completing mini quests. It's got a reasonable storyline, but the real stars are the songs. Real classic metal music from many of the greats of the genre. It's a fun ride through metal. I was given a PS3 copy for my birthday last year and I really enjoyed it, my mate and I are big metal heads. It's sort of a niche product but if you're into metal/heavy rock music you should get a kick out of it.