Ending months of speculation, Marvel Studios has released concept art (by Jackson Sze) for the Yellowjacket costume, as worn by Cross in the movie. As is obvious from the image, Yellowjacket is a variation on the Ant-Man technology with some obvious upgrades, including two mechanical arms with blades attached, which are almost guaranteed to be intended for troublemaking at some point.
In comic book continuity, Yellowjacket was an alternate superhero identity used by the original Ant-Man Hank Pym (Michael Douglas in the movie) that he adopted after an accident left him with amnesia and a more violent personality. The Yellowjacket costume was more weaponized than the original Ant-Man suit, which is apparently a tradition that the movie intends to honor, if not push even further.
Ant-Man, directed by Peyton Reed, will be in theaters July 17.