Reposted, bit updated. Fairly accurate for the next three years. Will be updated as we go (hopefully). Feel free to bring things to my attention (changes, new information about release dates or movies being worked on). Few aren't strictly comic films, but have a long history in comics (Conan, for instance). Where possible, linked to official movie site.
Dredd - 2000AD (or...whoever publishes 2000AD) - September 21, 2012
G.I. Joe: Retaliation - IDW - March 29, 2013
Iron Man 3 - Marvel - May 3, 2013
Man of Steel (Superman reboot) - DC - June 14, 2013
The Wolverine/Wolverine 2 - Marvel - July 23, 2013
Sin City: A Dame To Kill For - Dark Horse - October 4, 2013
Thor: The Dark World (Thor 2) - Marvel - November 8, 2013
Kick-Ass 2 - Icon/Marvel - 2013
Captain America: The Winter Soldier (Captain America 2) - Marvel - April 4, 2014
Amazing Spider-Man 2 - Marvel - May 2, 2014
Guardians of the Galaxy - Marvel - August 1, 2014
Transformers 4 - IDW - Alright, mainly a rumor, but an interesting one nonetheless. And likely, given the money to be made.
Ant-Man - Marvel - Test footage is done, script is done. It's definitely coming.
Elfquest - Epic/Marvel - in the works
Red Sonja - Dynamite - in the works
Deadpool - Marvel - in the works
Runaways - Marvel - something's happening
Incognito - Marvel/Icon - Fox has picked it up for development
Dr. Strange - Marvel - There are writers.
The Boys - Dynamite - It's coming along.
Bone - Warner Bros. has the rights, Jeff Smith's seen early animation work.
Suicide Squad - DC - And there's a video game, too.
Nemesis - Marvel/Icon - Tony Scott's directing\
Daredevil (new one) - Marvel - David Slade set to direct.
Teenage Mutant Ninja Turtles - IDW - Michael Bay's producing. I wonder if Shredder's going to be renamed Explodo.