Here are some official concept snippets by John Mann, who happens to be a storyboard artist for Iron Man 2. They were from his official site. Note that they are various snippets and aren't in any specific order. On his site he wrote "I am contractually obligated to not show any image here that might compromise the story or designs of iron man 2 until the film is released. therefore what you will see here are obvious little snippets that aren’t tied to any concepts or designs...enjoy!"
back-fall
eyes
girls
guard-center
guard-left
hand-up
Hot-Rod_w
micky
Run-COMBO-3_w
sight-locked
up-1
up-2