From the moment Captain America: Civil War was announced, I assumed it would use the "Whose Side Are You On?" concept the 2009 Marvel Comics event utilized. It's really brilliant in its way and I can totally see people putting "I'm with Cap" bumper stickers on their cars.
Incidentally, I'm with Cap.
YouTube and Comic Book Movie user MrSundayMovies discovered some artwork that appears to reveal both Captain America and Iron Man's coalitions of heroes. If you've read Civil War, a lot of these names won't be terribly surprising, but clearly some spoilers are ahead.
Tony's squad of wrong-headed losers includes War Machine, Black Widow, Black Panther and Vision. I'm going to assume Maria Hill backs Tony as well.
Which leaves a few people like Scarlet Witch and Spider-Man up for grabs, but it remains to be seen if this artwork is the real deal or someone's well-rendered educated guesses. None of these people are surprising for either team — War Machine backing Cap would be a true shocker — so it is possible an artist just extrapolated the current rumor atmosphere and visualized it. Then again it could be early mock-ups for marketing purposes, possibly even for the "I'm with Cap" merchandise.
And hopefully, you'll all be with Cap, too when Captain American: Civil War opens May 6th, 2016.
UPDATE: Jeremy Renner's official Facebook page now claims the art is genuine with the actor commenting "Got new threads. And I brought a friend" in regard to his image in the Team Cap artwork.