[UPDATE: Time to put the bunny back in the box. Sylvester Stallone told Deadline that he "has no knowledge of Nic Cage joining Expendables 3." He added that any reports that Cage was in negotiations for the film are false. This doesn't rule out Cage in Expendables 3, but he's no longer a confirmed member of the team. Now, if you'll excuse me, I think I have something in my eye. *sniffle*]
We mentioned that Nicolas Cage was attached to The Expendables 3 a while back, but further confirmation has come from Sylvester Stallone in an interview with the Spanish newspaper El País. In addition to Cage, Stallone also mentioned that he was hopeful for Harrison Ford, Wesley Snipes, and the return of Mickey Rourke. (Rourke turned down an appearance in The Expendables 2 to do Seven Psychopaths.)
The Film Stage posted this key excerpt from the interview, in what seems to be copy-and-paste translation straight from the internets (the best kind). Either that, or Stallone was really jet-lagged:
No word on what Cage's character will be like, but I'm hoping it's a combination of all characters he's played, and all weapons he uses bear his visage in some way.