CM4Sci over on Eurobricks has revealed what appears to be the official logo for the new theme that will be coming out in 2016 called LEGO Nexo Knights. The details of the theme are pretty scarce but it will be replacing LEGO Legends of Chima and will be bringing a Castle-type theme with hints of Steampunk. The story will revolve around some hero characters named Clay, Macy, Aaron, Robin, and Lance going up against some baddies named Jestro, Moltor, and Lavaria.
Rumor has it there are six building sets as well as six character sets named Ultimate (Character Name) which I assume will be Constraction/Ultrabuild sets. More details as they become available.