Eric Goldman is also reporting the Nick News that, although they didn't give an exact date or mention a specific month, Nickelodeon did confirm at their Animation press event that Nick USA will be debuting brand new episodes of Nickelodeon's new original animated series (Nicktoon) "Legend of Korra" later this year, and to celebrate, Nick showed attendees of the Animation press event a very special action sequence from "Book Two: Spirits", the second part of season one!:
At Nickelodeon animation press event. Teenage Mutant Ninja Turtles Season 1 finale in August - Season 2 debuts in September! #TMNT - Tuesday 7th May 2013It was announced earlier this year that the North American actress, comedienne, writer, television producer, director and 2012 presidential nominee Roseanne Barr (also known as Roseanne Cherrie Barr) will be a special guest star in the season one finale of Nickelodeon's "Teenage Mutant Ninja Turtles". Roseanne Barr is expected to voice a TMNT character called 'Kraang Prime'.
No month/date for Korra's return yet, but they showed us an awesome action scene from Book 2, debuting "later this year" #korranation - Tuesday 7th May 2013.