Well, when they laid out the phase 2 timeline I assumed Ant Man was in there because, canonically, Ant Man was the one who built Ultron as part of a really dumb scheme to convince the other Avengers to like him again. But that was Hank Pym, the original Ant Man and a total wife-beater. Scott Lang is the one this movie is about though. He is the second Ant Man, and also they made Iron Man invent Ultron because, to quote Marvel Studios, "Fuck everybody who isn't Iron Man."
I was really excited about this movie when it was going to be directed by Edgar Wright because I thought it could be a funny, offbeat film that lightens the otherwise incredibly dark tone of Phase 2 (which is what Guardians of the Galaxy ended up being). He makes exactly the kind of movie I thought a superhero movie starring Paul Rudd should be. But when they canned him, I worried that it would kind of lose its way and not be able to decide what kind of movie it wanted to be. This trailer... makes it look like exactly that thing has happened. Paul Rudd looks like he's trying really hard to make this trailer funny and the director keeps shoving generic, ominous superhero movie shit in there to drown it out.