You all remember the "You Complete me" line in trailers that was ultimately cut from the final movie
this is the alternate scene/ opening where pepper throws his helmets and he jumps out and catches it.
http://www.youtube.com/watch?v=LJBm1IyJ624
I think the only thing that doesn't work is the opening on Stark with his head in the toilet. Not the best reintroduction to Tony after 2yrs away.
One could argue it foreshadows 'drunk Tony coping with death' later in the film but first thing in the film really wasn't ideal.
Oh, I think that's hilarious! How often do you a see a superhero film open with the superhero hungover? It would have been unique, clever, and fresh. Something new that totally fits with the type of superhero film Jon Favreau and Robert Downey Jr. were going for in the first film and failed to capture in the second film.