An event called Momocon was held a few days ago, with Steve Blum (voice of Amon), Sifu Kisu (martial arts master), and Sifu Rodriguez (consultant for Toph) being present for a question and answer session. 
Fans got a chance to have their questions asked, and two very interesting tid-bits of information were revealed. Firstl of all, we will be seeing a sub-style of Airbending. Sifu Kisu also said he knew who Lin Beifong's father is but has to keep mum. Hopefully this means we could be finding out soon enough.
While neither anything really ground-breaking nor confirmed for the upcoming Book 2, these little bits of information definitely get me a wee bit more excited for more Korra!