Thinking on Shape's comments about how hard it is to find other players, I think a star topography worm hole structure could help. The idea is to replace the linear worm holes that connect only two points with wormholes that connect three to ten systems. A given system would typically have only one wormhole sector. Entering the worm hole would jump you to a hyper space sector where you would fly to a worm hole exit to your destination system. The hyperspace sector would contain three to ten wormhole exits all within a few KM of each other. This hyperspace sector then becomes the choke point where players meet.

Wormhole hyperspace sectors within nations could be nation guarded. In grey space they would be excellent pvp opportunities.