There was an early draft of Marvels Thor script that was floating around, in that script the whole story dealt with Thor in the world of Asgard, his father issues with Odin, and his struggle with his evil-brother Loki who is trying to take over Asgard. Apparently there was no mention of the modern world.
Like all scripts 'Thor' has gone through some changes. The changes made to this script includes how Marvel will further the story of 'Thor' and how they plan to bring everything together for 'The Avengers'. Which means they have to find a way to bring Thor into our world Midgard.
IESB is reporting that the character of Donald Blake has been included at the end of the script. This character is esential to how Marvel will tie Thor into the Avengers, which is set in the Iron Man/Hulk time frame. It will explain how the Thor film will be set in Asgard and how they will bring the Norse God character into Midgard. It will all come together when Donald Blake discovers the powerful Norse hammer Mjolnir.
As you know Marvel has been building up to this. Donald Blake's name was mentioned in Hulk. During a scene in the Hospital he was paged in the hospital. There is also a scene in the film where Hulk is screaming at the lightning and thunder, after he throws a boulder in the sky There is something that falls out of it, that is not the shape of a rock. It has something to do with Thor. So in a way the stage is set for this to all come together.
Now is Thor sent to live amongst the humans with no memory of his life as Thor until he finds the hammer as in the comic book? I would think so, but of course this will all take place after we see Thor in his native land battling other Norse Gods in Asgard.
On top of all that, Kenneth Branagh will not only direct the film, but he will act in it as well. Not sure who he will play though.
I think this film and Captain America are going to turn out to be pretty incredible movies.