I think I read, it may have even been here (if it wasn't it was on imdb, sorry I can't provide a link to my information), that Jim Broadbent was going to play a professor at Cambridge. He also mentioned his part as a "cameo," and when asked if he was playing Marcus, he laughed. It would seem odd to me if they 1) made another actor play Marcus Brody at all, and 2) had two older professor types in this film. Especially in a film where they are concerned about an older Indy, older sidekicks seems like a really dangerous move. My bet is that Hurt will play a villian, since he does so well in those types of roles. He probably won't be the only one, but probably the big head behind a group of evil-doers. Like that guy in Star Wars (sorry, I've only seen the original once), but he's the one with the black cape and talks in a real raspy voice, sits in a chair, talks to Darth Vader, anyway, he'll probably be something like that, but with more action, hopefully.