I liked it a lot. It's a comic intro movie, it's purpose is to show the character, establish a background, and set him up for later movies (in this case the avengers).
There was plenty of action, excellent special effects, and a storyline which tried to pay homage to the comics (well considering that a Thor movie that had all the comics plots and twists in it would be in the 150 hour range, I think they did pretty well considering everything they had to cut out).
If you're a comic books fan of Thor, it's an enjoyable movie. I don't go to a movie based on comic books or graphic novels to see a huge deep oscar winning plot. I got to see good action and a faithful reproduction of the characters I'm familiar with on-screen.