The people behind Damnatus have now set up a petition that I've signed, and which I encourage everyone else to sign. If people like George Lucas and Paramount can allow fan-created films (and Paramount, like Games Workshop, allow fanfiction).
Now I know they're particularly picky about army builders, as I was on the wrong end of that at one point, but fan-created films are just the next step on from fan-created rules or fan-created conversions, stories and artwork. All of them provide extra (good) promotion for GW, and all of them are the fans showing their appreciation and love of the mythology. I can see this only ever ending up as a bad thing for GW.
Even worse, GW Legal have gone to the extent that they've added a specific exclusion to their Can Do, Can't Do page:
MOVIES
The video games that our licensing partners have created have done an incredible job of bringing the Warhammer and Warhammer 40,000 games to life, and we appreciate that hobbyists may even want to make movies based upon our intellectual property. Unfortunately, due to the nuances of the law in some territories, we cannot allow any unlicensed movies to be created which are based upon our intellectual property.
I wonder if it'll ever be leaked to BitTorrent and make it as an underground P2P thing
More detail is available on the Damnatus news page.