They specifically said there wasn't going to be any new content in the march 31st patch. And they are working on DoW3 now.
They haven't announced anything and they refuse to talk about what's being worked on because they know if they just told everyone "Were done with COH2, sorry" the entire community would just throw it's hands up in the air and quit.
Except that they are constantly saying they are working on a warspoils overhaul, amongst other things.