I hate how the game doesn't make the towns more alive, people actually hammering away at making swords, instead of standing there, not blinking, like drones.
I love the guards in Lions Arch, they actually walk around and do their job.
Personally, I'm hoping for a more living breathing towns, where the ships actually sail away eventually, and you can actually (Oh man...so hard to impliment) WALK into stores and shops, instead of everything being outside.
What happens when it rains?

I think this alone could sell more copies of Nightfall, a more real world.