Loki himself, Tom Hiddleston, has revealed that Thor 2 will begin filming this summer in London.
The actor speaking with fans in an online chat at Empire broke the news and even teased about Loki's army:
I have no idea. And without revealing too much, there's a specific skill set you need to be Loki's army - let me know if you have the qualifications. And all I know about Thor 2 is that we're supposed to film it in London in the summer and that it's being directed by Alan Taylor.
Thanks to SHH for the info.
Thor 2 has a November 15th, 2013 release date.