5. Vanaheim
This is the home of the Vanir the sister race of the sir, and exists on the same planetoid as Asgard. It is also the realm of trolls and ogres. The Vanir include the all-seeing, all-hearing sentry Heimdall and The Goddess of War Sif. Both Heimdall and Sif will have expanded roles in The Dark World. The romance between Thor and Sif was played down in the first film in favour of Jane Foster. Jaimie Alexander who plays Sif has said that The Dark World has more character development for Sif and that it explores the Sif-Thor relationship.
6. Alfheim
This is the home of the Light Elves and Fairies and exists on the same planetoid as Asgard. The Light Elves are more like traditional depictions of elves, such as those in Tolkien's Middle-Earth. It will be difficult for Marvel to compete with Tolkien's elves already put in film, but to have a character like Legolas fighting side by side with Thor can only be a good thing.