Marvel Studios President Kevin Feige gave an update for Thor 2, the upcoming sequel to the Thor movie starring Chris Hemsworth, and said that Thanos won’t be the villain:
“We’re going to see the other side of Asgard. It’s not all polished and golden in this film. And the events of Avengers will have affected Thor for sure. His relationship with Loki will continue to evolve, and the biggest part is Natalie and Thor returning with Jane Foster.[…] there will be a major new villain. A major, major new antagonist…”
Kevin Feige
People speculating that the next villain could actually be the Enchantress, a powerful sorceress.
:)