Maybe the 3 hour run time was done on purpose?
I don't know if Denis and Hollywood are smart enough but here's the theory:
Denis makes another slow but beautiful and futuristic Sci Fi flick. It makes enough box office to get WB their money back..but the payoff is there's enough awesomeness in the movie that it will eventually develop a cult following, thus a constant stream of revenue for a long time to come.
Just like the original!