Evangeline Lilly has shared a picture of her new Ant-Man do and it very much resembles the Silver Age locks of Janet Van Dyne (less so the pixie-ish look modern day Janet sported). She is, of course, playing Hope Van Dyne, daughter of Hank Pym and Janet, and until San Diego Comic Con officially known as Hope Pym.
Here's a 1968 Janet that reminds me of this look:
Does the haircut and the name change indicate that Lilly is going to be playing The Wasp in this movie? Unless the script has changed drastically, no. She is certainly being set up for that role in the future, but before Peyton Reed came on the film Hope had no superheroing duties in the film. Reed - working with Adam McKay and other writers - may have changed that, but I suspect that the large adjustments to VFX would make that unlikely. Maybe we'll get a look at Lilly in a Wasp suit at the end of the movie, but take down the excitement for The Wasp one notch or so.
By the way, there have been some claims that Janet Van Dyne was 'fridged' before the movie opens. Again, I don't have working knowledge of the latest draft of the Ant-Man script, but previous drafts had her 'gone,' not dead. That's vague, and could mean Janet is lost in the Microverse, ready to show up in a future film. Also, technically speaking, having Hank Pym be a widower isn't the same as fridging Janet - there are specific things that go into fridging, and they're about using the death of a woman to motivate a male character.