The Castlevania series is the focus of much speculation right now thanks to rumors suggesting that Konami is planning to reveal two new titles at 2012's E3 in June. First up is Castlevania: Mirror of Fate, a rumored Nintendo 3DS game from the same producer and director behind the console release, Castlevania: Lords of Shadow.
Dutch website N1ntendo reported the rumor in a now-removed post that referenced an invite from Konami to a pre-E3 event where the game would be revealed. Lords of Shadow producer David Cox responded to a fan query on Twitter with the suggestion that the report is misinformed, though as Polygon points out, Konami does own web domains connected with the title Castlevania: Mirror of Fate.
The second rumor comes from Paul Gale Network, the same site that first brought word of Sony's now-confirmed PlayStation All-Stars Battle Royale, as GamesRadar points out. According to PGN, Konami will be revealing a sequel to Castlevania: Lords of Shadow in time for E3 2012 coverage. That game would be coming to PlayStation 3, Xbox 360, and Wii U.
Assuming that these assorted rumors are based in truth, I would speculate that we'll be seeing two reveals and that the initial rumor slipped up on a few of the details. My guess would be that Castlevania: Mirror of Fate is indeed a 3DS game, but Lords of Shadow dev Mercury Steam is actually working Lords of Shadow 2 while another team handles the Nintendo game.
Cox's comment about the original rumor being "misinformed" certainly supports that theory. Whatever the truth is, we'll know it soon enough.