Just because every boss hasn't shown up in the trailer doesn't mean they've been cut out :

That being said, being the long time fan that I have to say that this is the first trailer that seemed significantly non-Castlevania, though, it's really more non-Kojima Castlevania than non-Castlevania in general. It doesn't have that elegant black gothic feel to it, but if the last Castlevania game had been Rondo of Blood, much more so Super Castlevania IV, I could definitely see how you could jump to this point.
None of that's a bad thing, though. The trailer was excellent, and I'm really more excited for the game than I was at first, and that's saying something. If Jason Isaacs is Dracula, he has to be the guy in the hood with the mask. There are lines from the extended Gamescom trailer in the new trailer that match up with the voice of the masked man.
I'm also very interested about the shot of Gabriel with the Devil Mask shards on his face. FORESHADOWING.
Also, I'm calling it now, Claudia is going to become evil.