Pardon me if this has been already discussed here.

Now that release date being talked about is not in two or three years, I am just wondering whether recommended (or, absolute minimum) system spec to run this sim with the given details in decent enough frame rate has been known yet?

A week or two back on the banana forums Oleg himself said he was waiting until SoW BoB was released before he was going to upgrade his home computer. Sage advice Other than that Oleg is saying nothing.
I'm still saving ...

RedToo.

Yes wait until it released. Harware is changing all the time and antyhing you buy today will have been replaced and/or come down in price by the time the game comes out so hang fire until you have it installed and can see what's needed.