[Related Link: Whoops! CAPTAIN AMERICA 2 Actor Frank Grillo Teases 'Evolution' of CROSSBONES, Then Deletes Tweet]
Now, per Zap2It.com, Grillo has officially confirmed that Rumlow will definitely evolve into Crossbones by the end of the Cap sequel.
"They're introducing a character who—I'm not saying anything out of place here—but starts out as Rumlow and becomes the Crossbones. That's what this film is about [for my character]. Rumlow comes into this as one thing and... eventually, hopefully, if it goes well, you'll see this guy change. Something happens."
So Crossbones is indeed coming to the big screen, eventually. Yet Marvel Studios is known for adapting and changing things known in the comic universe so how Crossbones may look remains to be seen. Heck, and this is speculation, Crossbones could be adapted into being a modern day Red Skull after getting injected with some serum a la Cap, Johann Schmidt and Emil Blonsky before him.
Just a thought but one that The Daily SuperHero can seriously be seen as happening since actors are instructed to mislead the media before the release of a movie by saying one thing and meaning something else. Example: When Guy Pearce said he had a small role in Iron Man 3 but turned out to be the main villain.