I been to the movies quite a lot recently, and seen Cloud Atlas, Iron Man 3 and Star Trek Into Darkness. These movies have got me thinking about audiences like me and my Dad, we want something smart, yet with a reasonable pace and a few action sequences, most of all if it is a sequel we want to have a relatively different plot (I'm looking at you Iron Man).
There are very few film possibilities that Hollywood haven't explored, Vimes is one of them. Like most of Terry Pratchett's books, it's fun, but it also makes you think a little, and each book in the watch series has a distinctly different plot.
More and more I'm thinking that Hollywood needs Vimes.
(Other possibilities are the long earth, or Stephen Baxter's flood sires (perhaps in 4 parts)