I think races and classes will be a little bit more complicated than:
Clans=Classes in Vampire (you can be a thug Tremere or a scholar Brujah)
or
Tribe=Races in Werewolf (there's the breed thing as well)
There's a lot of additional factors to consider:
-Generation (I suspect this will be accomplished with templates, upgradable templates

)
-Auspice (templates, not upgradable)
-Breed (lupus..or the other two)
-Disciplines (some vampires focus on disciplines, others prefer attributes and abilities)
-Attributes (there's nine in the Storyteller system, six in d20)
I'm thinking that the classless system that's supposed to be in Call of Cthulu will be utilized in some way or another, but who knows? I just hope they can do it, without losing the feel to the original games.