Well, if you'd ask a Silent Hill fan, I bet he/she would argue that Konami only cares about Metal Gear and Castlevania. Silent Hill is, IMO, in a really really bad shape. Much worse than Castlevania ever was. And personally, I would probably trade a couple of years of Castlevania for just one more, proper Suikoden game. But that's never going to happen. Oh, and Gradius... and Contra.
I doubt Castlevania was ever in any real danger, it was more about Konami looking at games like God of War, thinking that they'd kill for a franchise like that. And Castlevania was the most obvious choice for that experiment. I doubt LoS2 will sell as much as LoS1, sequels rarely does (unless you're Assassin's Creed, God of War, Call of Duty or stuff like that), but with a little marketing maybe it'll sell... dunno.. 600-700K worldwide maybe, ps3/360/pc combined. Or something. Which isn't half bad.
Castlevania will never ever play with the big boys. I hope Konami have realistic expectations this time. They should, especially after Mirror of Flop.