One of the things I liked about the World of Darkness was the specific potential for telling very different stories in the same world. I guess that D&D was doing that for years previously, where you could cross dark stories into any setting by applying the Ravenloft rules to whatever setting you regularly played (or Spelljammer if you wanted pseudo-spacefaring, or Planescape if you wanted something a bit more metaphysical). But the World of Darkness claimed to produce distinctly different urban fantasy horror stories all set in a single rich world that didn't require jumping between worlds or planes to change the tone of each story. In this alley, werewolves were ripping apart a corporate executive who had greenlit a gas-mining exploration plant in a delicate ecosystem, while two alleys over a pair of vampires were delicately settling a blood feud that had been ongoing for centuries (by similarly pounding the crap out of each other).
In theory, you could run alternate weekly games with different sets of protagonists and different genres of story, but the same rotating roster of NPCs. In this vampire game Old Zeke is just a homeless guy who happens to have useful information about the local city blocks...in that werewolf game he's actually a kinfolk shaman who doesn't mind the vampires because they serve a role in the local city's ecosystem, and as long as they don't step out of line or become to powerful, he doesn't have to call in his big furry family members to put them back in their place.
It only ever got messy when the two genres actually did come into contact. What takes precedence, extra actions from Rage or Celerity? This power says it works against that attribute, but the other guys don't have that attribute... Every book seemed to have a new way of translating things between games, which worked well in tandem with another book, but contradicted two or three others.
The nWoD tried to remedy this with a core book, then making all of the creature games spin-offs from that basic structure. In that way, I thought it was good (in every other way, I found something to dislike about it... "WHAT NO KITSUNE! I'm outta here" [slams the door] )
My basic point here is that this new project "The Law" is basically very close to the direction I was heading with my earlier project "Familiar". Where one deals with keeping the peace in a crime ridden city, while the other deals with keeping magic alive in a city where the very essence of mysticism is dying. Agents of The Department of Law deal mainly with criminals, their goals are to maintain the peace and ensure the safety of citizens; this is done through investigation, establishing relationships with the local community, and dealing immediate justice when necessary. Familiars deal mainly with mystics and outsiders, their goals are to find artefacts and tomes of magic, containing them when dangerous, and releasing the energies within when the metaphysical balance needs realigning; this is also done through investigation and establishing relationships with the local community, but often needs to be done in a subversive manner to avoid the attention of the authorities.
Both games are about keeping the world in balance, one maintaning a balance of law, the other maintaining a balance of magic. Both try to keep dark things from spilling over into public view, but when one is a game about police, and the other could generally be considered a game about heists, it's easy to see how they could come into conflict. It would be just as easy to throw a few other types of games into the mix... perhaps a noir story system about private eyes who live in a grey area between the authorities, the criminals, and the metaphysical outsiders... perhaps my Tom Waits inspired game about gritty and rusted morality, focused on angels in a world where belief is both a cherished treasure and a sign of insidious insanity.
But the aim at the moment is to get one game working right.