I'm pretty sure they didn't buy the STALKER license, and if they did, what's the worst that could happen? Some bad writing or voice acting? Shitty animations? The originals already had that shit. Bethesda is great at overall world design and I don't think they could fuck up basic shooting/gameplay mechanics, 'long as they don't use Gamebryo.
Hell, as a Fallout fan since the start, I didn't even really mind Fallout 3. Wasn't great, but it wasn't terrible. It also made way for New Vegas, and that's one of the only games /v/ fucking jacks off over.
I did and the thing that they ALWAYS fucking nail is the atmosphere. I unapologetically think Fallout 3 has the best atmosphere of any Fallout game, and Oblivion, for all its generic shit and horrible gameplay, had some pretty fucking gorgeous and fantastical environments, if not a bit too bloated and overly bloomy.