I assume Oleg is struggling as we speak to make all of SOW features work with usable framerates. So I doubt we will see any system specs info until the game is near gold. He may even have to delay some features until systems can take the load. SOW will be continually upgraded as new theaters and addons are created, much like IL-2 had done.
Oleg includes many options to adjust the game to suit your PC requirements. I've always preferred to fly with as many options enable as possible and can afford rather highend systems [atleast in my own mind, not my wifes]. So waiting a year or two after the games release to play the game properly is not an option I would even consider. That said, Oleg won't release a game only playable on these highend systems as it would be financial suicide.
If you build a 64 bit OS System with a 3 gig , 4 core cpu with atleast 6 gigs of ram, and a relatively highend videocard with options to upgrade the cpu later you should be able to turn quite a few options on. A solid state hard drive may also be very helpful.
Waiting a year and half after release,,LMFAO. We've had an 3 extra years and counting to save for this system, but I doubt many including myself have. I know its not a funny matter for those on more restricted budgets.