After an uncertain future, Nickelodeon Australia has announced The Legend of Korra will return.
BOOK 4 CONFIRMED FOR EARLY 2015 RELEASE IN AUSTRALIA, MEANING A US RELEASE HAS TO BE ON ITS WAY THEN OR EVEN EARLIER!!!!
"A Nickelodeon representative [told] IGN Book 4 will premiere in Australia in January/February 2015.”
Given this timeline and assuming it’s true, it’s possible Book 4 will premiere at New York Comic-Con (October 9th-12th) with online distribution following shortly after.