According to Harry Knowles: "Right now, there is a 1 minute demo of Iron Man 2 converted to high quality digital 3D ... Right now the suits at Marvel & Paramount & now also Disney are considering this 1 minute. At the same time that this is happening, they are fishing for bids with 3 different companies to see what the cost and time it would take to convert Iron Man 2 to a complete 3D film." There's also talk that if they actually pay to convert Iron Man 2 to 3D, they might also do the same to the first Iron Man and rerelease it into theaters next May. Watch Jon Favreau's Twitter to see if this comes true or not.
As Knowles points out, if it does come to pass it would certainly be a game-changer for the upcoming Marvel slate. You might see Captain America, Thor, or The Avengers behind a pair of dorky glasses. I'm not entirely sure how I feel about that, as I find the format too distracting to be enjoyable. But it would be a hell of a lot of fun to see Iron Man rereleased in 3D, and revamping an existing film seems better suited to this ongoing novelty than designing a film around some pop-out effects. I seem to be in the cranky minority when it comes to the 3D style though, and those who are enthusiastic for it are certainly winning the war for it.