Instancing in MMORPGs

MMORPG.com has published an editorial entitled "Instancing in MMORPGs", in which they offer their thoughts on why instancing isn't moving massively multiplayer games forward. A snippet:
If Ultima Online were at one end of the spectrum then Guild Wars would be at the other. The majority of the gameplay in Guild Wars is instanced. The only time you mix with other people is when you visit specific areas to trade and find groups. Whenever you go on a mission there is only you and the people you have invited, if you have not invited anyone then you are alone in what is at times a large area. Ok, so there's no camping, and the lag is pretty much non-existent but there are no people. I know the idea is to find a group to adventure with but how do you do this, the game doesn't promote any prior interaction so the only option you have at first is to commit to doing missions with random strangers. In my experience finding a good team was really difficult, although when I do the game is fantastic.