My first reaction would have been "Shisui's dead." However, after the whole Obito'sdeadlolznotreally incident, I would't doubt if his body is being used somehow. Whether it is actually him or not will hopefully be revealed soon enough.
Also, the fact that the guy shares the same MS as Shin in that one eye is rather interesting. It's definitely not Shisui's design but, until we see the other eye in action, it could just mean that it's a borrowed eye.