Variety reports that Evangeline Lilly is in talks to join Edgar Wright's Ant-Man as the female lead, a character intended to appear in more than one film. Nobody knows who this is - the trade is reporting she might be the daughter of Henry Pym, and the eventual love interest of Paul Rudd's Scott Lang, but Pym has no daughter in the comics - but everybody's going to start speculating that she's The Wasp.
In the comics The Winsome Wasp* is Janet Van Dyne, a socialite and the wife of Hank Pym, who shrinks down to a tiny size and, using her Wasp Sting blasters, fights villains. She's dead now, I think, but that changes weekly, so don't get too upset. At any rate, she's a pretty beloved character (truly), and she's tied deeply into the Ant-Man mythos, such as it is. Everybody expects to see her in the film.
And everybody's probably hoping that Evangeline Lilly, who is one of the best parts of the boring The Hobbit: The Desolation of Smaug, would only be in talks for the role if it were more than the love interest. We have enough love interests in the Marvel Cinematic Universe, it's time to get some women with super powers!
Don't get too excited about this casting; we've been seeing the trades running these 'in talks' stories earlier and earlier as superhero casting brings in the hits; it's very plausible Lilly doesn't take the part but Variety happily takes the web traffic.
*Marvel characters have the best full nicknames.