So according to everybody's favourite gaming news site Kotaku, Prey 2 is now being developed at Arkane which, now that I think about it, would make a whole bunch of sense. If there is anything to it, we probably hear about it during E3 I guess?
Also, here is a quote from Kotaku that makes me...happy. Just pure, raw happiness is flooding my veins right now. (and a whole bunch of doubt and disbelief too, but shut up! I'm happy!)
Higher-ups at Arkane are telling the team to forget that it's called Prey 2 and just treat it like a new System Shock.