Okay, the truth is: we don't know everything about Iron Man 2....YET. But there has been some groaning about some possible issues.
A) Whiplash doesn't appear to have any armor.
B) Possibly too many villains, like Spiderman 3.
C) The whole plot, in the trailer? and/or Justin Hammer issues
Have we seen too much in the trailers? Do we know for sure Whiplash has no super armor? We can have peace of mind that the movie will not suffer these infections, because we have been in the same situation before, with The Dark Knight.
As you can see, the trailer for The Dark Knight also reveals some plot info, but we already knew who the villains were! Joker, and Two-Face! Did the movie suck? Absolutely not.
Did we know Two-Face would "die"? Nope. Did we know Rachel would die? Nah. So...what do we have to fear? Nothing. Iron Man 2 is not in theaters yet. We still can be surprised. Who knows, maybe Whiplash does have armor. It will be awesome; of course they would hide it.