I think there is a big difference between pugs. In Rift, you only Pug with people from your own server. Hence, you are accountable for your actions. A Dungeonfinder for people on the same server is good tool and helps to build communities. The WoW Dungeon browser pretty much brought McDonalds attitude to pugging. A Dungeon became a fast snack, just something you want to get over with. The End. No accountabilty for fuck ups, nothing. I even argued with a long time guild mate about the horrible thing that represents the dungeon finder. It pretty much made me quit pugging alltogether. Whats the point, if you are going with four dicks into an instance, who you'll never see again. It's pretty much like chatroulette. A sea of dicks, where few decent people stick out.
I dearly hope, Bioware does not allow cross realm dungeon runs. It kills the server community, sadly.