I somehow feel that Bloodrayne Betrayal is proof that WayForward won't ever make a Castlevania game. They poured their 2D vampire heart into this one instead. Maybe because Konami just wouldn't let them have a go at the real stuff.
But who knows? They've established a relation with Konami, so it could happen someday. But I kinda don't think so anymore, not after seeing Bloodrayne. Unless Bloodrayne is a "hey konami! Look at our Castlevaniaesque game! Do you want one too?" kind of thing.