I don’t know how you feel about it, but without Stalker Complete, Shadow of Chernobyl felt rather broken IMO. It had tons of potential and great atmosphere, but it was a pretty obvious beta. Once the AI was tweaked, bugs fixed, localization improved, features added, and graphics improved, then it was stunning. Of course, it wasn’t a port like Skyrim, but it had its fair share of problems nonetheless.
Also, Skyrim and Stalker may have some overlapping traits, but I don’t think the core appeal is the same. Stalker is about fighting for your life on your own in a bleak, hostile environment that lives and breathes on its own and cares little what happens to you. Skyrim is about working your way to the pinnacle of whatever path you choose and having some adventures along your way to be the Big Damn Hero. I think that would be the real problem here - not that Bethesda would make another Stalker game left riddled with bugs and lackluster graphics, but that the core appeal of the game might be changed.