In speaking with Total Film, Vaughn compares the film to Batman Begins, but says that any sequels would be completely different from the tone set by Christopher Nolan's movies...
Vaughn: “First Class is similar to Batman Begins, where you have the fun of introducing the characters and getting to know them, but that takes time. “But with the second one you can just get on with it and have a rollicking good time,” he continues. “That’s the main difference between Begins and The Dark Knight.”
While the 1962 setting gives Vaughn and Co. the chance to explore the the themes that are the very heart of the X-men's reason for existence, that of fighting prejudice and promoting racial and species equality, Bryan Singer hints that any sequels could possibly take place in the 1970s or...oh my goodness...the 1980s!! Ack!
Singer: “That’s an idea that’s been discussed,”How the characters go through time. But only to a point – they can’t age too fast!”
If you want to get a glimpse of how the X-men might look in the 1980s, all you need to do is read some of Chris Claremont's comics from the time period. Storm with a mohawk, disco queen Dazzler in hot pants. It was a riot!