If you haven't heard, Paul Rudd will play Marvel's Ant Man.  Ant Man will kick off Marvel's "phase 3."  Basically, each Marvel "phase" ends with an Avengers movie.

If you're not familiar with Ant Man, he's a scientist who invents a substance that allows him to change his size, but retain his strength, and he's also a founding member of the Avengers.  Apparently, according to the comic, Ant Man feels the Avengers don't take him seriously, so he invents Ultron so he can destroy him and prove himself to the Avengers, but Ultron goes nutzoid.  Now, the villain in Avengers 2 is Ultron, the robot invented by Ant Man, yet Ant Man isn't making his film debut until after Avengers 2.  Are you as confused as I am?

Ant Man will be directed by Shaun of the Dead directed Edgar Wright and should open in the summer/winter of 2015.