RDJs not a collegue gradguate?
Who knew.
I got TDK and it really isn't that smart or hard to understand at all.
The characters are really only as smart as the subplots allow them to be and there are a lot of subplots to be had in this movie that go beyond just beating the badguy. Also there is a lot that happens and revolves around Begins. Both movies alone have more context than most mainstream genre movies combined
Personally I felt the same way RDJ did after seeing Spiderman 3. The problem there was the subplots were poorly concieved and as much as Rami tried to hold it together in the end everything was just unconvincing and silly.
Best of luck though to RDJ and Iron Man 2 The first rocked and was smart enough and well excecuted to stand out well enough this Summer.

Also Iron Man is not Batman. Both comic book based, and similar but Batman unlike Iron Man has been around a lot longer and been explored as a charater to the point of exhaustion and Iron Man is still wet behind the ears and carries a much different back story and Universe. Iron Man doesn't need to be smart or complicated, just fun and properly excecuted and it'll make sales, guaranteed.
What worked in TDK regarding complexity wouldn't IMO work with Iron Man. I hope the creators/people involved stick to what works and not try to flesh out every concievable subplot/character in the way TDK did.
Give me Iron Man. War Machine, a kickass villain and I'm sold.