So Robert Downey Jnr is going to be Iron Man? I thought that at the end of 2 they ruled that out?
I'm not sure where that rumor came from as Downey Jnr signed up to be in The Avengers movie before they started filming Iron Man as did Chris Helmsworth, Sam Jackson and Chris Evans. It was actually a part of all the movie contracts because The Avengers movie was always the ultimate goal. The only one who didn't sign one of these pre-contracts was Ed Norton which is why he isn't back as Bruce Banner.
I found it to be rather dull and uninteresting, I'm more excited because this may become another X-Men: First Class, and I'm a Firefly fanboy.
There were a lot of slow parts to Thor but what they did was lay the ground work for the future movies. They didn't have to explain the Cosmic Cube in Captain America because we already saw it in Thor. Similarly we won't need any lenghty introduction to Loki and the Asgard mythos in The Avengers because they already did that in Thor. It harmed the Thor movie a little but you could say that movie took one for the team.