I should first off say that I don't know a huge amount about Thor's cannon except from the Ultimates and Civil War series as well as bits and pieces here and there like Beta Ray Bill but I wasn't expecting that to be addressed anytime soon.
I honestly wasn't familiar with the characters past Thor, Loki and Odin but I don't find that a hinderance seeing as that means I came into the movie without my typical "geek eyes" on like I did with X-men, The Watchmen, Iron Man or even when I watched the abortion that was Rob Zombie's Halloween remake.
I can say that although I was really looking for some more epic action I totally dug the film. It could have taken itself too seriously since Thor is obviously steeped in Norse mythology but it gives you a good Marvel interpretation of the material and without getting too heady on us. Caveat to that, I'm not say that a heady comic book movie is bad just that it wasn't talking over the head of the audience.
Asgard was beautiful as I imagined it would be. Anthony Hopkins was great and restrained enough when dealing with the Shakespearean power struggles.
Chris Helmsworth was damn near perfect casting as the titular character. He got the fish out of water confusion that Thor experiences once he comes to the "Earth realm". As per usual in the stand alone comic book movies they have to add a love story even if this one wasn't fully realized like other superhero films (cough*Superman Returns*cough). I love Natalie Portman and her role worked well enough without making you roll your eyes.
And a nice shout to Stellan Skarsgard for his scene stealing especially in the bar scene or I should say after. It was pitch perfect. Same goes for Kat Denning, more so for her comic relief, keeping things lite in the right spots.
Tom Hiddleston, wow was he amazing. He almost drew sympathy into the typically mischievous Loki. You felt a bit of his pain in being second fiddle to Thor in the eyes of Odin. Totally believable as to his motivations. I am looking forward to him as the main? villian in The Avengers next year.
I did expect the movie to be longer and was surprised when I began to realize the story was wrapping up. Not to give too many spoilers but I thought that Thor would have remained on Earth a while longer considering how he ended up there but I suppose they plan on bring him back in The Avengers so I guess its understandable.
I was really sad to see the Hawkeye cameo was so little and wasted. Great to show he will be in the Avengers BUT I'd have loved to see a bit more of his relationship with S.H.E.I.L.D. Again I suppose its another reason to watch The Avengers. Sucks though that this is all leading up to that movie and then what...? Spin off movies or a sequel to the star studded ensemble film? I have no idea. Probably both.
Also sad we didn't see Tony Stark, though he was mentioned a few times or any illusions to Captain America since thats the next attraction in two months time.
Overall I'd give the movie a "B" bordering on "B+". Very entertaining but more or less just a way of not having to explain too much when Thor shows up in the Avengers movie.
PS. loved the matte paintings throughout the film.