First look at footage of Book 2
Looks really solid, I love the character designs of the spirits. Still no release date announced, we may have to wait until Comiccon for that announcement.
EDIT: Also, A soundtrack for Book 1 of Korra will be released. fans have been asking Nickelodeon for a soundtrack for Avatar The Last Airbender for years with no success, but for Korra, the Track Team invented a new genre of music (jazz if jazz had been invented in China), so a soundtrack seems like a no-brainier.