Why wouldn't he?
Iron Man and Sherlock Holmes, 2 roles that he can carry on for as long as he chooses and would be mad to give up. Iron Man especially, he plays Stark perfectly, cannot imagine anyone else in the role.
Well he can continue with Iron Man in The Avengers 2/3. Although he's great in the role, he is getting a little older now, he might some day want to to tone down the action.