Antrax, it seems that you really dont't want this to be a Castlevania, but why? This could be the great game we wished, let Alucard alone, IGA game is different and it will kick asses, but the Kojima game could be the real surprise. Kojima is a very deep man, under his hand, Castlevania could become the epic saga we always dreamt of.
I think this will be a new castle; I see the mask, and one word comes to my mind: Carmilla.
Gabriel (Belmont)'s Armor is very similar to the one in Simon's Quest, and considering that Carmilla's first appereance was CV II, could this be a prequel to Cv 1? Is Gabriel Simon's Father? I hope that.
And the rumor is about to be confirmed. For me, the artwork with the castle is enough, but if you want more proofs ,the article that unveiled this rumor said that the new MGS would be named Peace Walker, and so it was.
Let's wait until tomorrow, I hope there are 2 new Castlevanias coming!