Movie adaption of Night Watch

I recently re-read Night Watch, and I know Terry Pratchett books are notoriously difficult to adapt to the big screen... but by golly would I love to see it.

I would love to see James McAvoy or Christian Bale take a stab at playing Vimes. They are both nearly the right age AND have the range to convey the character, I think.

It's time we get a modern mini series or something. The Discworld books are a treasure trove and I wouldn't complain for more - whatever the medium.