Well, thanks to Box Office Mojo, I think we can safely say the grand experiment of "Chronicles of Riddick" has come to an end. It cost $140 million to make, and as of now grossed $50 million worldwide. Its attendance dropped 61% in the second weekend. It's been panned by critics. I'm doubting there will ever be a sequel, so Riddick's character will never return. That's a shame, because I still think Riddick was the character Vin Diesel was born to play, and he was awesome. Too bad about all the evil. On the plus side, rumors are floating about Vin Diesel playing Lex Luthor in the next Superman movie, which (to me) would be a dream cast on the level of Patrick Stewart playing Professor X.
Also check out this interview in USA Today with Vin Diesel. It's got a more complex picture of the guy than I've heard before.