A Dark Souls PC release is incoming. All of the evidence points in that direction. The most telling sign is an ad in PC Powerplay magazine (via All Games Beta) for next month's issue that bears the all-too-familiar "You Died" text that players see whenever one Dark Souls beastie or another pounds their hero into paste.
Simple math there: Dark Souls death screen + ad for next month's issue in a PC gaming magazine = Dark Souls: PC Edition announcement.
But wait! There's more! A newly launched announcement page on the Dark Souls Facebook page is teasing some sort of reveal that will happen after enough people "Like" the FB app. It's not quite as obvious as the Dark Souls death screen in a PC gaming magazine, but I would be surprised if these two things turned out to be unrelated. All of this comes on the heels of the fan-launched Dark Souls PC release petition that Namco Bandai cryptically commented on in January 2012.