Guild Wars 2

A really good “living world” feature in Guild Wars 2 would be the events happening in the world affecting the trading post, for example, when the refugees all came to town in the Frost & Flame story, there should have been a shortage of some food supply, for example bread or grain, which would then make the NPC traders have less or no supply. This would then mean prices for items that are normally a few copper pieces on the trading post could go up in price. There are lots of other possibilities, seasonal items (no strawberries in Winter for example) or other affects due to events that happen in the world.

This would make the economy even more “alive” and would make trading a lot more interesting than it is, especially for someone that got lucky and happened to have a load of bread dough saved up etc.