Pump more iron in your movie diet this summer. Marvel Studios launched the newest trailer for the upcoming “Iron Man 3” on Yahoo movies and it jolted the Internet with the force of a repulsor blast. Scroll down for video. “I'm Tony Stark, I build neat stuff, I've got a great girl and occasionally I save the world, so why can't I sleep,” says Robert Downey Jr.’s tormented billionaire in an opening voiceover. It could be because of the enigmatic menace of the mysterious badguy behind the third installment of the Iron Man franchise, the first two installments of which earned $1.2 billion at the box office worldwide. “You'll never see me coming,” says Sir Ben Kingsley’s heavily cloaked Mandarin. “I'm going to offer you a choice, an empty life or a meaningful death.” Judging by the montage of action scenes hurtling by over the two-minute, 30-second trailer, Tony Stark seems bent on the latter. Most intriguing is the trailer’s money shot: dozens of Iron...