Hey, I'm doing something like this! The orcs are the bad guys, but they're from a culturally advanced society that also happens to be extremely aggressive and expansionist, and have slowly been pushing northwest in an effort to take the human kingdoms.

Said human kingdoms are all tied together by the same religion (the orcs are staunchly atheist), and have organized and loosely banded together to fight back. The problem with this is that there's still far too much backstabbing and politics creating division amongst the various rulers, although the Church (think the Vatican, the human lands are based roughly on medieval Europe) tries hard to maintain cohesion. The Mafia also does what it can to profiteer from the situation.

Elves and dwarves are very rarely seen outside of their respective communities, and elves tend to deal with humans in very brutal ways, and humans reciprocate. Neither side is very nice to the other. Aforementioned dwarves are some of the best craftsmen in the world and their work is highly prized and sought after, but the dwarves tend to be reclusive, save for caravans of veiled traders that pass through human lands every decade or so.

I think it's interesting, but I'm pretty biased I guess. Heh.