"You've got to do the Mandarin. The problem with the Mandarin is that the way it's depicted in the comic books, you don't want to see that. He has 10 magical rings — that just doesn't feel right for our franchise. So it's either tech-based, or the rings are not really rings. But maybe with 'Thor' and all those others, you'll introduce magic to that world and it won't seem so out of place."
Director Jon Favreau
I hope the Mandarin will be played by some Chinese-looking actor (like in the comics) and not by a middle-eastern guy...
By the way, Marvel announced that they're planning to release Iron man 3 in 2013.