I'd love to see a new style of victory condition, a cumulative victory point win.
That is to say : currently, if 5 VPs are enough to win the game, as soon as someone gets them all, game over, allowing stealth victories, surprise victories, and even accidental victories. Not that this is a bad thing.
But Alneyan's King of the Hill games are essentially a cumulative VP condition : One key province (the Hill), and whoever holds it for a total of 20 turns wins, with everyone knowing each turn who holds the Hill and how many turns everyone has held it.
This really inspires the fighting - no one wants to let someone else come close to holding the Hill for 20 turns, and as anyone starts to get close, epic attempts to wrest control of the Hill take place.
But it takes the person hosting it to make this work.
So, what I'd like to see is a way to have fixed victory point locations on a map, and the game keep track of how many turns each player has held those VPs, along with a mandatory score graph displaying the gradual accumulation of those victory points. (This particular score graph would be on, even if graphs were turned off.)
This would promote conflict, and keep games from running on too long - once the victory provinces are taken, the scores start accumulating. I can imagine new maps being created with places of power, holy sites / cities, etc, that serve as the victory provinces, as well as old maps which already depict such places being modified for this style of game.
I think it would also make for more intense games, with hot spots of interest and conflict surrounding all the victory provinces. Do people expand in all directions aiming to build up enough strength for the victory sites, or head straight towards them? Given that there's a definate time constraint, people can't just meander about building clams and gobbling independents, not once someone starts accumulating the victory points.