One thing that characterized the Iron Man comics was the multitude of power-armored suits that Tony Stark had at his disposal, and Jon Favreau has cryptically hinted via Twitter that Robert Downey Jr.'s Tony Stark might have new suits of armor on hand in Iron Man 2.
On April 13, Favreau wrote:
@jon_favreau Completing work in one set today with Mickey, then into Tony's workshop tomorrow with RDJ.
If Downey is going to have any significant scenes in Tony Stark's workshop, that suggests that either the existing Iron Man MK III armor is going to get damaged and need repairs, or that Tony will be working on a MK IV set of armor. Of course, it is equally possible that Tony's work in the lab is meant to transform the MK II suit (the all silver set) into the War Machine armor for Rhodey (Don Cheadle) to wear.
Iron Man 2, directed by Jon Favreau, will continue the tale of Tony Stark and his armored alter-ego as he continues his transformation from billionaire industrialist to super-hero. Robert Downey, Jr. will star as Tony Stark, with Paltrow returning in the role of his assistant Pepper Potts. Don Cheadle, Mickey Rourke, Sam Rockwell, Scarlett Johansson and Samuel L. Jackson also star. Iron Man 2 blasts into theatres May 7, 2010.