Robert Downey Jr. and Gwyneth Paltrow have an even spicier relationship in Iron Man than we'd expected, judging from this newly released trailer. And the use of AC/DC lets us know this movie will have big balls. (Sorry, couldn't resist.) More importantly, the new trailer gives us a way clearer sense of the movie's arc.

We get a nice clear view of the three phases of Iron Man armor in the movie: crude, medium crude, and shiny. Also, we'll definitely get the full storyline from the comics about Tony Stark's pride, and then remorse, about being a weapons maker. It looks as though his change of heart is what turns his mentor Obadiah Stane into his arch-enemy Ironmonger.

Oh hey, and here's a new (I think) plot synopsis:

Based on the long-running Marvel comic book series, Iron Man tells the story of Tony Stark, the enigmatic heir to the Stark Enterprises fortune. A driven inventor and executive who seems to have it all, Tony is haunted by his dark side. Though he commands his empire by day, by night he secretly becomes Iron Man, the living embodiment of decades of defense spending and innovation. Strapping on billions of dollars worth of state-of-the-art armor and weaponry each night to fight crime, terrorism and corporate espionage, Tony begins to crack under the strain of his fractured lifestyle and must ultimately confront the one enemy he can never beat — himself.