I think they've said that the Civil War is not going to be so much about registration/unmasking (since the Marvel heroes dont really have secret identitites) but just a philisophical difference between Tony and Capt.
Which could be really great since they've been kinda setting it up so you can see each POV from the last two movies where Tony is desperate to be prepared for any threat and Capt. refuses to compromise his principles for safety. And with Tony creating Ultron I imagine that will only intensify the divide.
i just hope they dont do another spider-man origin story. Do like they did with the Ed Norton Hulk where the origin is covered quickly in the opening credits and then the movie starts with him already spider-man. No need for explanation. With some creative editing they could probably compress ALL the previous movies into one backstory with
the origin, Dafoes green goblin, death of gwen, harry osborne's arc, and mary jane and peter getting together.