Konami has already committed to bringing Castlevania: Lords of Shadow 2 to the PC, but it might be letting players catch up with the first one as well. A recent update to the Steam registry suggests that Lords of Shadow is coming to the PC soon.
The registry update spotted by DSOGaming (via RPS) was fairly recent, having only popped up over the weekend. Konami hasn't made a formal announcement, so it's hard to tell just when the game might become available. Shacknews has contacted Konami and will update as more information becomes available.