This really isn't a Fable 4 game.
It's based in the Fable universe, but I wouldn't class it as a continuation.
And while I agree with Molyneux being a part of whether this sinks or swims, the biggest thing is going to be whether its on or off rails. If it on rails like it looked at E3, this game will fail. If its not, it has a chance with it being one of the first 'major hardcore' Kinect titles.