Lucas Till has joined the cast of X-Men: First Class, reportedly as the mutant brother of Cyclops, Alexander "Havok" Summers. Word of the casting comes from Entertainment Weekly, but the article also points out that this news may be a bit of misdirection on the part of Fox, who want to keep some of the roles a surprise.
Havok would be a logical choice for a story featuring a younger Scott Summers. He first appeared fairly early on in the X-Men mythos, resentful of Scott’s boy scout attitude. Able to control plasma blasts, Havok went on to star in his own spinoff title, X-Factor.
Check out the trailer for the previous X-film, X-Men Origins: Wolverine below: