I'm going to keep this brief.
The original Iron Man was a breath of fresh air in the superhero genre. Robert Downey Jr. was awesome, it was snarky, fun, and well cast. Iron Man 2 retains some of the positives from the original but also suffers from a lot of sequel fever. First off, there are waaaay too many characters going on here. Scarlett Johansson is hot but completely unnecessary, and gives a stiff awkward performance. Gwyneth Paltrow is lovely as always, and is one of the only characters in the movie that really works. Then you've got Don Cheadle stepping in as Tony's bff "Rhoadie." Note to blockbuster movies; Never ever ever ever ever switch actors midway through a series. The audience notices. Duh. You just don't do it. Look at how crappy the Batman franchise got after they ditched Michael Keaton. Now I could forgive this but Cheadle also gives a crappy stiff performance. Should have brought back Terrance Howard...just sayin'. So basically the plot goes as follows, the world is now aware that Tony Stark is Iron Man and the army wants to weaponize the suite. Tony doesn't. Then we have a vengeful Russian (Mickey Rourke) out for Stark's blood. Said Russian creates sweet whiplash suit in his little basement laboratory, and somehow it's actually believable. Nice touch. Rourke actually pulls off the roll with some grace, and I realllly enjoyed the badass character. The action sequences are excellent, and I think every guy out there will be drooling over all the sweet technology. Overall, Iron Man 2 makes a few missteps but nothing huge or unforgivable. Robert Downey Jr continues his unprecedented career resurrection and I really hope he keeps it rolling. The guy is crazy likable. Decent flick.