It'll probably be bad, if the current trend is anything to go by. I didn't really care about the first game, but I thought the second one was brilliant. Brotherhood was OK, but not quite as good as II. Revelations was kind of a mess, lots of really out-of-character moments for the series. And 3 is just...boring. The setting just isn't doing it for me. There's no especially tall or impressive buildings to climb, but there's lots of features that add pretty much nothing for me. (Hunting, tree-running, The Homestead, etc.)
Yeah. Well. We'll see.
EDIT: Also, and this is completely irrelevant, but I think it's weird that they gave it a subtitle despite it being a full sequel.