I think I'd honestly rather see a Marines vs. something else film. The Marines vs. Aliens thing has been done - exceptionally well in Aliens, and to death in the EU.
Personally, I feel there's plenty of stories the big screen could tell with the USCM (including comic adaptations). ALIENS may be legend in its own right, but I could easily see a new film expand on their equipment, scope of operation, ranks/leadership and relation to WY, new characters and more Xenos to fight on new worlds. The idea of Xenos infesting multiple worlds in the human sphere makes for a large scale universe outside one event on one planetoid.
Honestly, I'd be happy if FOX greenlit productions of all the main DH novel adaptations like Rogue, Labyrinth, Genocide, etc. Even if they were cartoons or live action tv shows.