Stark captures the Big Bad in the first act, has a chat with him in prison where the villain sends a cryptic message, only to fake his death a little while later and come back to menace the hero. Sound familiar?
Cowboy Bebop at His Computer: A ridiculous number of reviews refer to Scarlett Johansson's character as "Natalie Rushman," the false identity she uses when she first appears in the film. Understandable if the reviewer is attempting to avoid spoiling the character's true identity (thought neither the movie's advertising campaign nor the movie itself are particularly subtle about it) but clueless in reviews that go on to identify her as the Black Widow. Moviefone calling her "Natasha Rushman" didn't help.
And has proceeded to spew Take Thats at Marvel, the director, and even the other actors in every interview he gave.
Considering how often the page has Whiplash as an antivillain, while still not being allowed a free pass of course, it seems his sheer performance and a few tidbits were plenty to gain Whiplash that status.
Doing It for the Art: Rourke improvised a lot of Vanko's characteristics, such as his toothpick habit, his fondness for cockatoos, and his tattoos. He paid for the cockatoo with his own money, learned to speak Russian, and visited the infamous Butyrka prison to interview the prisoners there, who he described as very polite.
Executive Meddling: Director Jon Favreau had a lot of friction with the Marvel higher-ups, to the point that rewrites were happening as the film was still shooting. In particular, elements such as the increased prominence of the SHIELD subplot were the result of a need to establish the greater Marvel Cinematic Universe in preparation for The Avengers, at the expense of the coherence of Iron Man 2's own plot. These disputes got so bad that Favreau turned down directing Iron Man 3.
Scenes that fleshed out Ivan Vanko and portrayed him as a more sympathetic figure were cut from the final film, resulting in him appearing to be a more generic villain. This may a reason why Rourke has stated he is not fond of his experience working on the film.
James Rhodes was played by Terrence Howard in the first Iron Man movie. Here, he's played by Don Cheadle. His first scene is framed in such a way that his face isn't visible until after Tony greets him, so that the audience is clear on who he is.
Real-Life Relative: Sam Rockwell and Leslie Bibb are a couple in Real Life. Her presence in this film is a bit of an ironic coincidence. First Bibb was cast in the small but pivotal role of Christine Everhart in the original Iron Man, then she began dating Rockwell, then Rockwell was cast as Justin Hammer for this film, and when the producers found out he was dating the actress who played Christine in the first film, they brought back her character as Hammer's uninterested date.