I think Kalin has a point with the idea of several "nations" forming a kind of conglomorate in order to make themselves stronger by sharing resources as well as the idea of there being several resource types that give different options for tech advancement. I would go so far as to say that these kinds of alliances would be a natural part of any game that actually tries to simulate "world" politics and economies.
I have 2 ideas on the matter.
1. Why not make it possible to actually make nations? Russia, the US, Germany, Greece and even China all started as seperate and independent city-states or states (Germany was actually tribal, but close enough). All of these pre-nations were divided based on family lines except for the US, which was based on who originally settled a specific area (same principle though. "My great-great grandfather settled this land. That makes it MY land, not YOUR land.) I understand that the game world is going to be "run" by ruling families who serve as avatars for the player. Why not allow those families to create full blown nations? One ruling family would serve as the "federal" government from the strongest "state". The rest of the states would serve their own interests, but still be under the protection/rule/law/etc. of the nation as a whole. This is different from a simple alliance because allies have no ability to influence or control each other besides "if you don't do this then we're not allies". As any stategy gamer knows, this is hardly motivation to do or not do anything most of the time. If instead it were "if you don't do this then you're going to be one little tiny nation against who knows how many big nations" it would be pretty good reason to stick around. Until you just get fed up...which makes my next point.
2. Thoughout history ruling parties within nations have changed. This can be by social reform (France: Viva La Revolution!), political backstabbing (Caesar), or full on civil war (well... just about every nation out there) to name a few methods. It's not hard to imagine one state grabbing up land, growing stronger, and then either turning on the ruling party directly or getting a good number of the states to back him/her up.
These ideas don't really conflict with my previous ones. The labor/quality of life advantage I talked about for new players wouldn't really apply if a player decided to cede from a nation. They would have the same QOL as the nation they split from (which would very likely be much higher than a new player's). The whole idea of this would be to make it REALLY hard to cede from a nation without that nation's blessing (like "yeah, you an leave, and we'll protect you for X number of turns/days/weeks"). It's a built in saftey measure against using the nation idea as an exploit (Join nation, get rich, get tech, ditch nation, try to conquer it or otherwise backstab). I mean, if I belonged to the United State's of Phyziks and one of Kalin's states decided to try the above, I'd be more than happy to pounce on that state and take it for my own (or if we're friends then assist in the retaking).
Guess that's enough for one post. Got lots of historically based ideas for the politics of a virtual world, but can't really post them all at once. 