The original ‘Iron Man’ earned high marks from critics and audiences for its light tone and humor, as much as for its action. Duplicating box office success likely won’t be hard, with fans primed for the 2010 summer season’s first big franchise installment.

‘Iron Man 2,’ picks up six months after the end of ‘Iron Man,’ with Ivan Vanko (Mickey Rourke,) a Russian ex-con, plotting his revenge against Tony Stark – and building his own variation on the Iron Man suit to mount his challenge. Vanko becomes Whiplash, who is a very different character, at least on the surface, than his pen-and-ink antecedent.

We recently had the opportunity to speak with director Jon Favreau, and first wondered what the pressures had been like to build a worthy sequel? "It’s like throwing a party and you don’t know if people are going to show up,” retorts Favreau, comparing the making this sequel to that of the first film. “Here, we knew people were going to show up and we wanted to make sure everybody had a good time.”

And what can you tell us of 'Whiplash'? "Whiplash, in the comic book is a guy wearing tights with a big plume, a big purple feather coming out of the top his head,” says Favreau. “That wasn’t what we wanted. But, we asked what’s the tech version of that?”

Whiplash’s counterpart in ‘Iron Man 2’ is unscrupulous industrialist Justin Hammer, played with gusto by Sam Rockwell, who was once up for the role of Stark himself. Originally, Favreau says, Rockwell and Rourke’s characters were one – but in later drafts, were divided into two: the brutal Whiplash, and smarmy Hammer.

Still, Favreau was well aware of the stumbling blocks of many previous superhero sequels. “The trick is to feather villains in, so they don’t overwhelm the story and you don’t suffer from villainitis,” he explains. “By having Justin Hammer and Mickey Rourke’s character come together fairly early, you really have two storylines that are weaving. You don’t have five separate storylines… We really tried to keep narrative flows going so it didn’t get too convoluted, ‘cause I lose track of that stuff."

"Especially in sequels as franchises get more complex, I don’t always remember what happened in the last movie. Not for nothing, I like watching stuff blow up, but I don’t want to do homework before I see a sequel.”

In the role of Tony Stark’s friend James “Rhodey” Rhodes, Don Cheadle stepped in to replace actor Terence Howard, and despite speculation that this might have made for contention between Cheadle and Howard, Cheadle said there was no bad blood: “Terence is a friend. We’re cool.”