The double whammy of Iron Man
will, in my opinion, keep the green lights coming for superhero films at a fast pace over the next couple of years. In particular I think Warners will finally break the development logjam and give the go-ahead to some DC superhero films outside of Batman and Superman.
If Singer gets to make a sequel to Superman Returns
he'll obviously put an immense effort into making it a crowd-pleasing film with plenty of action. He'd have marching orders from the studio to that effect in any event, and he'd be well aware of the need to deliver. I'm not entirely sure we'll get such a sequel, though.