In most MMOs the players have little to no effect on the game world itself. I would love to see the players set the world's path.

I think it would be interesting if there was a form of player government.

Basically X amount of players are elected by their fellow players as counsel to the grand company leaders, one set of players for each city state.

From there they can set companies goals. If they give grand companies some kind of point or currency then completing the set goals will give more currency and therefore give players more reason to listen to counsel choices. The counsel could set to many different goals. They may wish to boost the economy with higher emphasis on gathering jobs. Making markets more profitable and (if they add housing) the housing market more affordable. But the areas around the cities as well as city defenses may suffer, as outer areas get more dangerous as less players are doing missions to clear the roads between cities, and the city is less defended from attacks on itself and its hamlets as less guards have newly crafted equipment.

Of course the ways players could affect the world could be much more diverse than just these things. Really the above mentioned things are just suggestions. But the idea of players having some real, visible and noticeable affect on the world around them would add a great dynamic to the world.