Iron Man 2 was bleh.
The 3rd will most likely be even more bleh.
As far as super hero movies go, Iron Man 1 was a near masterpiece.
It didn't go overboard with the amount of characters, it focused on dialogue and character development rather than explosions, and it rebooted Robert Downey Jr's career!
As far as I can tell, the 3rd movie will just be one long advertisement for just about everything Marvel related.
Hell, SpiderMan will probably just pop out of nowhere and introduce himself into the plot Samuel L Jackson-style.