I'm definitely excited. IM2 hinted at dealing with stark's issues with alcoholism, which could be either incredibly done or will look like a stupid local radio add made by high school students to try and keep parents from buying booze for their kids.

I get the feeling that magic will be something that at least sort of is explained in a somewhat scientific manner. Besides, there have been promo photos of the infinity gauntlet (i think that's what it's called) since thor. Now THAT is something that i'm skeptical they'll be able to explain with just science.