Thor is exactly what it should be. It was never going to be as great of a movie as Iron Man, but not many superhero movies will be. Thor is exciting, fun, and entertaining. It's a great prelude to Avengers, and I would totally get excited for a second Thor edition.
I thought they did a great job with the movie. By splitting it into two films, they are able to stay with the book much more than usual. The liberties they took worked pretty well.
The only thing they didn't explain to people was what happened with Harry Potter and Voldemort in the opening scene for people who don't know the book.
I thought the comic relief was done well to sorta lighten to mood of the movie without dominating the story.
For starters, this movie was amazing. The best of the year. You must see it in 3-D. It's a masterpiece. I loved everything about the universe that James Cameron created. You get completely immersed in it from the get go. The length of the movie is never a problem. Nothing slows to a halt. You never check your watch.
All that being said, the force fed liberal propaganda almost made me throw up in my mouth. It would be 100% possible to make the story as great as it is now without the ridiculous Anti-American sentiment.
To use the lines "shock and awe" and "fight terror with terror" is a travesty. I hope all the books, sequels, and prequels lose the political agenda. The universe of Avatar will flourish just the same without it.