Like you say, it won't take ridiculous specs in order to play it. If the performance isn't quite as high as it might have been otherwise, I'm sure it's still just fine if it's good enough for the HD consoles. Besides, the PC version is still the one to own because of all the mods that will come down the pipe. Wouldn't surprise me if there will even be a texture mod or somesuch eventually, upgrading the game's graphics to take advantage of higher end systems.

On the one hand the users shouldn't have to improve the developers' game, but on the other hand the fact that they can is awesome and frequently leads to great results.