I really like the way that WoW did its factions. Having primarily two sides which the players can join in the fight limits how that player is going to start out. They might be able to join smaller factions as they progress and gain honor or reputation with other groups, but they always remain a member of eiher the Horde, or the Alliance.
I think we get this in Dungeons and Dragons for the most part going back a long ways, but probably not so clearly stated. You usually see a strong alliance between the majority of humanoid races i.e. humans, elves, dwarfs, halflings, and even half-orcs. The rest of the world is pretty much on the other side of the wall and may or may not be all on the same side.
Sure, in D&D things are more complicated. Individual kingdoms have their own agendas, politics, blah blah blah. However, if the far realm were to invade the world, these kingdoms would probably put their problems behind them in order to fight off armies of Mind Flayers.
These racial alliances really boil down to factions. I want to establish these racial factions in my game to make it clear to the players and to people looking at the world, who likes and dislikes who, from a very wide and general point of view. If you look at L5R, you get this to some extent with each of the clans. Maybe it is a bit different in terms of flavor, but you can see these same Large scale alliance coming into the picture there.
The Lore of the World at this point stands with the various humanoid races at the center of the world aligned together for the last few millenia. The Beastfolk Noble Races were, at the beginning of this alliance, all united into one. However, What I want to see happening is having these beastfolk races gradually growing apart and warring against each other. The fracturing of the Beastial Alliance begins the factioning process and several factions (maybe 3 or 4 racial factions develop).
What do you think about my analysis of the factions idea and about how I would use it in my world?