The big draw of Marvel's 2006 Civil War storyline is that it split the entire superhero community right down the middle, so you had a team led by Captain America facing a team led by Iron Man. And all of this over a Superhuman Registration Act enforced by the government to keep heroes in line. In the Marvel Cinematic Universe things are a bit different. There aren't as many heroes flying around (yet), but there will still be an ideological split. A big question has been how the sides will be divided up in Captain America: Civil War, and now a rumor has surfaced at Heroic Hollywood that claims to know the breakdown. Possible spoilers, of course.
What we already know is that T'Challa aka Black Panther (Chadwick Boseman) won't be picking sides in this fight. As the king of Wakanda, and generally mistrustful of Americans, he's staying neutral and looking out for his nation's interests. As for Captain America, he's on the anti-registration side and joining him will be Hawkeye, The Falcon, Scarlet Witch, Ant-Man, and The Winter Soldier. None of those choices are very surprising except for maybe the Winter Soldier (Sebastian Stan), who apparently will have recovered from decades of brainwashing pretty nicely.
Iron Man's pro-reg squad consists of Vision, Spider-Man, Black Widow, and his pal War Machine. It will be interesting to see if they have Spidey switching sides as he did in the comic. Rumors are that Iron Man will be an integral part of Spidey's upcoming solo movie, perhaps even designing his new costume, so maybe he'll stick around on Stark's team.
While the Avengers are busy slapping one another around, Black Panther will be off doing his own thing, perhaps motivated by the death of someone close to him. The site also says that Black Panther's father, T'Chaka, will die at some point in the film. It isn't clear how that will happen but with family nemesis Ulysses Klaw (Andy Serkis) expected to appear hey's probably involved somehow. In the comics T'Chaka was the head chief of Wakanda and the previous Black Panther. Despite his nation's vast technological advancements due to its use of the precious metal Vibranium, T'Chaka hoped to stick to the old Wakandan traditions, which meant no formal ties with any outside nations. He was eventually killed by Klaw, leaving the throne open for T'Challa to claim some time later. Despite some other sites claiming Ernie Hudson is set to play T'Chaka that has never been confirmed by Marvel.
Lots to consider, but remember these are just rumors for now.