Check out this interview Playboy did with "Schafes", I guess as a push from "Hef", about the Making of Brutal Legend. I can't tell you if it's spoilerish or not, because I didn't read the whole thing in fear of spoilers. Yes, I haven't played yet. The shame is killing me. (On the other hand, I did buy it! Twice!).
There's also a very spoilerish section on how Ophelia came to life.
Last, but not least: You can play against Tim Schafer himself in Brutal Legend. Add him as a friend on PSN or XBLA, but make sure you have the game first (he won't accept your friend request without you having a copy). He's TimOfLegend.
Update: Here's Tim's (for the extreme among you, sort of spoilerish) response for those bemoaning that Brutal Legend is an RTS: It isn't.