A fear that a lot of artists have is that once they have gotten success at a certain level if they grow, change, or do something different, their fans will leave them, hate them, and/or crucify them. Judas Priest are ending up on the recieving end of that judging by what I have read in the forums.
Judas Priest are always willing to try something different. They can't give you another British Steel, another Screaming For Vengeance, or even another Painkiller. As for Nostradamus, I haven't listened to the whole album, but I liked what I have heard so far.