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 (opens in new tab) . 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 (opens in new tab) seems.
NeoGAF member Nabs spotted the game (opens in new tab) 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.