Though some new movie stuffs arent bad at all - for example i enjoyed
StarSHipTroopers RoughNecks animated series - absolutely great work!

http://www.misterhook.net/roughnecks/index.htm

This movie is far more mutant chronicles
like than the same named we know was

- "Aliens Vs Zombies"!

IMHO I think that an instead of a potentially "expensive epic war movie" a different approach could be refreshing.

Namely a TV series.

Either one featuring a Luna PD investigation series or one a Freelancer working for the different corporations, exploring the MC universe as the series evolves.
My reasoning for this is that the MC mythos is quite intricate for the average joe (not the fanatics, though...) and gradually exploring and investigating it makes more sense and is more easily grasped. And in that way you could have both good stories to tell and the rich background as a supplement...

/Cheers

Or how about some great turn based startegy video game mods?
I prefer this because its a stressless pleasure of enjoying any fictional settings.
Good games for modding could be: Jagged Alliance 2 or Panzer General 2 which
was greatly converted in already two WH40k games.