Steamdatabasemancy is a word referring to fine art of gazing into the Steam database, to try and foretell the future of PC gaming. As with looking into a cup of tea or playing the stock market, it's an art that disappoints as often as it... appoints, with right-on leaks like Brutal Legend and Dyad just about making up for misleading Halo 3 entries . So you should probably take the addition of the original Castlevania: Lords of Shadow with a pinch of salt (and maybe a couple of cloves of garlic), despite how legit its entry seems.
NeoGAF member Nabs spotted the game yesterday, which is curiously listed as "Castlevania: Lords of Shadow Early Access Comp". The 'billingtype' is also down as "Proof of Prepurchase Only", leading us to believe that the original game may be offered as a pre-order bonus for the sequel, which has yet to appear on Steam.
If and when it does arrive, we're likely in for a treat (well, if the port's up to scratch), as MercurySteam's reboot of the ancient Castlevania series rather impressed me when it first arrived back in 2010. Lords of Shadow 2 - which does have a confirmed PC version - is currently on track for later this year.