Tony Stark creates a new element in "Iron Man 2," though it's no big deal. Robert Downey Jr.'s zillionaire genius, who was revealed to be Iron Man at the end of the previous film, simply builds himself an in-home particle accelerator, fires it up and then bango, he's got a...new element. This sequel, unfortunately, settles for a new alloy of old elements - less iron, lots more lead and tin.