Comic fans are used to the phrase "it will change everything" when it comes to the latest and greatest event. Whether it is Secret Invasion (did), Fear Itself (didn't), or House of M (really did, but only for a small subset of people), the promise is always that the next event will have long-lasting reverberations for years to come.
Now Marvel's Captain America: Civil War is singing the same tune. In BuzzFeed's Q&A the question (via bloodstaind-ballgowns) was asked: "Can you tell us if/how this/these conflicts(s) will alter personal relationships and friendships in the group going forward?"
Chris Evans chimed in first, saying "They will change the dynamic FOREVER but I don't want to give anything away so you will have to see the movie like everybody else!"
Joe Russo agreed that Civil War would have numerous ramifications.
"There will be a long-lasting fallout from the events of this movie. It will significantly alter the psychology of the Marvel Cinematic Universe moving forward."
While I tend to not buy into these type of statements when it comes to the books, with the films Marvel has a much smaller scope compared to dealing with 40 to 60 monthly books, and the planting seeds of effects in each one, and trying to get them all to align. While a death has been rumored, it hasn't been confirmed. That said, that would definitely hit these characters extremely hard.