Robert Downey Jr made 6,000 Comic-Con fans sing 'Happy Birthday' to Jon Favreau's son Max before allowing them to see the world's first glimpse at Iron Man 2 footage.

Boy, was it worth the wait.

Favreau's amped-up super-cast look out of this world: an eye-patched, black-clad Samuel L Jackson as Nick Fury swaps banter with Downey Jr's Tony Stark, who shows off his razor wit in court as the government try to steal his supersuit.

Mickey Rourke looks sensational as Whiplash, thrashing the ground with twin electro-whips while Stark lies dazed and bleeding on the ground. Sam Rockwell primes another effortlessly cool performance as Justin Hammer, who tools up Don Cheadle to the max as War Machine. 

Even more than the glimpse of a flame-haired Scarlett Johansson kicking ass, it was a final shot of War Machine - guns blazing from every angle - that really blew the roof off Comic-Con buzzing Hall H.

"We just wrapped literally last week," said Favreau. "Everything started here two years ago. You're the people we wanted to show this stuff to first." Favreau then mentioned an Avengers film. The roof exploded off again.

Looking funny, thrilling, stylish and even more spectacular than the original, Iron Man 2 already could be hard to beat as next summer's hot blockbuster. 2010 suddenly seems a long, long way away.