I've waiting for them too, but only one thing is for sure: the game will be BIG (like in HD size), as it uses ID Tech 5 lol. Perhaps you should take a look -for now- at Wolfenstein: The New Order requirements (which uses the same engine), as I bet they will be similar (but, of course that I'm just speculating).
That game is a monster. If Evil Within is close to that I *might* be able to play it. Never thought I'd be considering upgrades this soon, lol (this is my first true gaming PC).