"If they can't support everyone into 1 town there is no way there will ever have a good PK system."
Dude that doesn't even make sense. What does that have to do with a good PK system. Each instance can hold about 100 people, if not more. That's plenty for implimentation of a PK system. You want 10000v10000?
Either way, guild wars goal wasn't for a PK system. It was for balanced PvP. Right now it is very close.