The Ninja will be back sometime in 2014! I'll tell you what I've managed to uncover.
Since the defeat of the Overlord, things have been in peace in New Ninjago City, and there seems to be a new incorporation, sorta like the Yggdrasill Corporation from Gaim. Anyway, the Ninja are given all new outfits and new weapons to fight a new evil robotic force! Their new weapons are called "TechnoBlades" which allow the Ninja to use their enemies mechs to their adventage, or as Jay would put it "What do you say we do a little hack attack!"
Anyway, for unknown reasons, Sensei Wu will join the bad guys and there will be more Nindroids, much to everyone's shock. So now it's up to Garmadon to be the Ninja's new Sensei in order to save Ninjago from this new threat... GO NINJA GO!