Saw it last night, I thought it was good and I enjoyed it, although I did feel slightly underwhelmed. I think the film felt a bit unbalanced as the first 20 mins/half hour or so felt really epic. The second part just couldn't live up to that. The attack on the frost giants home world was really good, but the fight with The Destroyer didn't have the same impact.
I preferred the fight with Loki rather than the one with The Destroyer as it had more emotional resonance. It had some nice nods to the Marvel universe and there were a lot of funny lines and moments.
High Points:
The casting was excellent. The family dynamic between Odin, Thor and Loki was great to watch. Heimdall was totally badass. Sif and The Warriors Three offered good moments.
The humour of the film was good, it didn't feel forced. My favourite line was probably when the Shield agents saw Sif and the Warriors Three walk down the street and they said "We have Xena, Jackie Chan and Robin Hood"
Asgard looked magnificent, especially liked the Rainbow Bridge.
The assault on the frost giants.
Minor Criticisms/nitpicks:
I didn't feel they needed to have the opening scene with the science team crashing into Thor and then repeat the scene later on.
I didn't really like the way Thor regained his hammer. I mean, the spell was "Whoever holds this hammer, shall he be worthy, will possess the power of Thor". Which is fair enough, I would have preferred it had Thor actually held the hammer as he died. Although one of my friends pointed out that Odin shed a tear, so maybe he willed Mjolnir back to Thor.
Hawkeye:
Enjoyed Hawkeye's cameo although I don't understand why he'd even reach for the sniper rifle before the bow.
End Credits Scene:
I was quite amused because pretty much everyone in the cinema was completely nonplussed by it. After Iron Man 2 there was an excitement because people actually recognised Mjolnir. I guess the same isn't true for the cube. Although I don't think too many people were really into comic books because there wasn't much of a reaction when Donald Blake was used.
I did like how it managed to establish that Thor returned, and the reveal that Loki was present added extra excitement.
I kind of want Nick Fury and Odin to meet so they talk about eye patches
Roll on Captain America!