Iron Man 2 picks up not long after the first film. Tony Stark is dying of Palladium poisoning from the arc-reactor embedded in his chest, he is coming under increasing pressure to turn over the Iron Man suit to the US government, especially when a new threat in the form of Whiplash, the alter ego of Ivan Vanko, a Russian physicist with some strong grievances against Stark.
Overall, I had a great time with this film. I really enjoyed the first one, and I get the sense that the studios have learned a lot from the relative flops that were the Spiderman sequels. There are some good nods to the comics, especially with the inclusion of Nick Fury and the SHIELD initiative.