Whoooooo!
To answer some of the points from the OP:
The movie takes place not long after the first, and clearly, the people from S.H.I.E.L.D. are beginning to become involved with the early Sam Jackson spot, as well as Black Widow (Johansen). Probably. She's had a long history with the Avengers, so it will be interesting to see how she factors in. Rourke is playing Whiplash, a relic of the Cold War, using Ton'y Repulsor Ray technology to settle (what I understand) is a family dispute. Keep in mind that in the Marvel Universe, Poppa Stark helped make the atom bomb, and that's part of the reason why their weapons company is so powerful today. Sam Worthington's character is the head of a rival weapons firm, I believe his character was supposed to be a classmate of Tony's at MIT. How that will work, I'm not sure yet (I'm guessing he's the one who puts the Repulsor Ray tech out there for the naughty people to get).
Anyway, its going to be an awesome movie, which is going to set things up nicely for the Avengers movie in 2011. The only thing I'm left wondering is what other parts of the Marvel Universe will be wound in. Will it be Thor? Something with Captain America? What about something from Hulk, again?
EDIT: daan's question
I believe that plays out in the movie, which is where Black Widow and the rest of S.H.I.E.L.D. comes in. Probably. To protect Tony, his company, and his technology.
