http://www.amazon.com/Revolution-Nickelodeon-Legend-Korra-Junior/dp/0449815544/
We now have the cover and title of the Korra junior novelization that was revealed by Amazon a few weeks back.
It is called The Legend Of Korra: Revolution. Also we should note the 1 at the top which suggests that more are coming, perhaps each book is getting a novel like this or maybe this only covers part of Book 1 Air. It is still 256 pages and will release January 8th 2013.
