Namco Bandai spent E3 carefully managing expectations for the upcoming PC port of Dark Souls. They've said that From Software aren't doing much to optimise the game on PC, but hope that the addition of new areas and bosses will make up for those shortcomings. It'd be reasonable to worry that Dark Souls PC might come with the bloated hard disk and processor requirements common among clumsy ports, but according to the system requirements spotted on the updated Steam page by Eurogamer that's not the case. If you've got a dual-core CPU, Dark Souls will sit primly on 4GB of HDD.
More curiously, Dark Souls PC's multiplayer mode "requires" a microphone headset, which suggests vocal communication will be an integral part of the upgraded multiplayer features that From Software are adding to the Prepare to Die edition.
Update: The mention of a microphone requirement was an error, Namco Bandai inform EG that Dark Souls PC won't support in-game chat. Bum.
Still, on PC we'll still be able to use any number of external chat programs to stay in touch with co-op companions, but there's potentially a bit of fun to be had with mic support. I'd like it to record my agonised cry of "nyaaargh!" every time I die, stacking each frustrated noise on top of the next with every death until my failures are met by an echoing cacophony of my own eternal frustration. I will also use it to say "lol" when Chris falls off something.
And now, for your eyeballs, some system specs.