We definately need Non Instanced dungeons in this game. There is no point in playing an MMO where you cannot meet people at random throughout the game. Why would we play a Massive Multiplayer Game if we only see eachother in town. There is a reason the first GW was awful. At the very least if the HAVE to make all Dungeons instanced, they need to make them Public Instances. We NEED places where multiple parties can come in contact with each other. 0 competition is a game breaker. Worse yet, 0 collaboration is a game breaker. An Auto Party function can only go so far. yes it will allow you to complete content. But how are you going to make friends? If everyone you meet up with is on another server, you will never be able to play with them outside of a small group timed instance. Your friend will never be able to meet other friend. In all likely hood, you will never see the same person twice. 100% instance dungeons is a horrible idea.
On top of all that, a content finder is going to make it so you never have to travel to the location of the content. This means people will not be leaving town. Which means your not going to meet people in the field either.
