Well, neither Pratchett or his publishers are known to frequent this site, but I've never heard of a Reaper Man movie that has been made, or will be made, with the exception of a guy's personal project to try and make his own animated version.

Looking at the DV Studios website, they don't even mention Reaper Man as a project and again they look like quite a small scale studio - I doubt they could even afford to buy the rights to make a commercial film.