The Wasp was originally expected to appear in The Avengers (she even appeared in some early storyboards), but Marvel decided to give Edgar Wright a little more time to make Ant-Man, stopping both characters from being founding members of that team as they are in the comics. It's a great shame that they've both been absent from the Marvel Cinematic Universe for so long, but that is obviously going to change next month when "Phase 2" comes to a close with Ant-Man.
Talking at a press event for Ant-Man yesterday, Kevin Feige had this to say about what's next for The Wasp (WARNING: POSSIBLE SPOILER AHEAD). "We have plans for her in the future, and we see that not-so-subtly in this film [Ant-Man]."
That confirms that Hope may end up suiting up by the time the credits roll then, but where could we see her next? Ant-Man 2 hasn't been confirmed, so perhaps Hope will join Paul Rudd's Scott Lang in Captain America: Civil War?
Either way, it sounds like we're finally going to see The Wasp on the big screen very soon!