I personally would rather have this separate so we don't have the main thread bogged down by this and can instead devote it to productive discussion of actual news.
Ant-Man is not the greatest Marvel character in the world. To be honest, I normally would not be that excited. That being said, there are two things that excite me:
1. The fact that this movie "sold" Marvel on the idea of Ant-Man. I get the impression that, were it not for Edgar Wright, Ant-Man would never be incorporated into the movie universe. Instead, we're not only getting an Ant-Man movie, but they've been planning for the moment of its arrival for quite some time.
2. The movie seems to be "different." It's been described as a heist movie. It won't just be another Iron Man. Just like The Winter Soldier tried to do something different, I think this movie will feel very different. That alone will probably make it worth watching. Marvel has shown that it seeks quality, so a quality heist movie with ties to the universe as a whole seems promising.
ETA: For what it's worth, I hope Pym is an A-hole. By having him older and not the hero of the movie, I think it works well. He could have his demons and made mistakes in the past (but still was a flawed hero). Then he passes the torch to the new Ant-Man as someone who can be a better person than he was.