It seems like Marvel Studios is currently considering moving forward with Iron Man 2 without the involvement of director Jon Favreau. Despite the great success of Iron Man, much of which is credited to Favreau's involvement, according to a report from IESB.net, Marvel may be looking to go forward without him due to money disputes.
According to reports, Favreau directed the first Iron Man for a very modest fee, and was looking for a slight bump in his fee for the sequel film. However, despite the financial success of Iron Man, Marvel Studios chairman David Maisel is apparently unwilling to pay a higher fee to Favreau. Reportedly, the studio believes the film will be a success whether or not Favreau is involved.
Official statements from Marvel still say that negotiations between the studio and Favreau are still ongoing. Despite this, Favreau claimed on his MySpace forum that "It's been five weeks since the one and only phone call my reps have gotten from Marvel."