By Nicole Sperling
Updated July 26, 2009 at 04:20 AM EDT

“Nobody cared about Iron Man until we came here,” said director Jon Favreau, returning to Comic-Con to offer a packed and amped-up crowd in Hall H an advance taste of Iron Man 2. (The hall was so crowded, even Marvel executives had difficulty getting in.) Favreau was joined on the stage by stars Robert Downey Jr. (who plays Tony Stark/Iron Man), Sam Rockwell (who plays sleazy arms merchant Justin Hammer), Don Cheadle (taking over the role of Jim Rhodes from Terrence Howard), and Scarlett Johansson (who plays Natasha Romanoff/Black Widow — and who drew audible gasps from the audience.)

Favreau kicked things off with a deliberately cheesy-looking introduction that resembled a low-budget marketing clip. “What was that unadulterated garbage?!” Downey asked, feigning outrage. “This is bulls—, dude! You showed me better stuff in the editing room!”

Then, after a pause to acknowledge Favreau’s son’s 8th birthday with a mass sing-a-long of “Happy Birthday,” the real footage began. Fans saw about five minutes of footage, including Samuel Jackson as Nick Fury finding Iron Man eating donuts; Garry Shandling as a senator asking for control of the Iron Man weapon; Cheadle as Rhodey transformed into War Machine; Johannson as Black Widow; and Mickey Rourke as new baddie Ivan Vanko/Whiplash, complete with deadly lightning whips. (The footage was shown twice at Cheadle’s request.)

Though Johansson joked that her audition for the film consisted of “a couple of deep knee bends and lunges,” she drew praise from Favreau: “All the fighting and wire work is her own. She worked really hard and it shows on the screen.”

Cheadle addressed the slightly awkward challenge of stepping in to replace Howard, who fell out of the sequel in a salary dispute. “We addressed it elegantly and then moved on,” he said. “But I willsay, being the vampire that I am, I siphoned off everything I could from Terrence’s performance and then modernized it for 2009.”

Speaking of co-star Rourke, Downey deadpanned, “And I thought I was eccentric.” Favreau said Rourke did research for the role by spending time in a Russian prison, noting wryly, “You know, after Perestroika, the first film to arrive in Russia was 9 1/2 weeks. Mickey’s a sex god in Russia.”