I think she makes the ironman series; she's the woman that bruce wayne never really has, and I think really brings a light-hearted and personal side of Ironman.

You're right, this seems much, much darker than previous Ironmen. ;)

It doesn't hurt to have Christopher Nolan favorite Guy Pearce in it, too.

And I'm happy to see Don Cheadle and Scarlett Johannson returning, too.

Robert Downey Jr is committed to the Avengers sequel as well. That makes five movies as Ironman, at least.

Avengers is the #4 box office movie of all time.

Dark Knight is #3. So clearly they have aspirations to go higher. :)

(#1 and #2 are Avatar and Titanic, but neither of those is a superhero movie.)