I think a nifty server idea would be one that focuses on combat between two opposing teams. My vision is there are two kingdoms, lets say an east and a west kingdom. You start in a some sort of dmz or "neutral territory". You can enlist to be a soldier of either kingdom, and you cant switch (unless if you pay a fine or something that wouldnt allow players to swap teams easily, or make them want to swap teams at least).

The main goal would be to promote loyalty and nationalism, so pvp between the two sides as well as building a strong community within each kingdom are two key factors. I think it would be cool if the economy of each kingdom is affected, to some degree, by what the players do. For example, if there's a tower that's held by one side for X amount of time, the kingdom gets a reward. This could be a new item, prize money, etc. There could also be player-made shops that would be expanded based on popularity. If players in your kingdom buy your stuff, you can eventually sell more items or something.

I don't know. It sounds really ambitious even though I didn't say much, but the basic idea is to build two separate communities on the same server that compete to be better than the other