I think a few of you might have guessed by now that I am not a huge fan of the LFG system. The priciple reasons being:

1: It is designed so good players will run morons through the game.
2: It encourages players to behave like fuckwits.
3: It kills any hope of finding good players on your own realm.
4: It is devoid of any game immersion.

That last one is the killer for me in Cataclysm. The three new 5 mans in patch 3.3 that came in with the LFG system, ie the Ice Crown 5 mans, were the first new instances to be run using only the LFG system. And what they were was an exercise in sprint management. I did them on the night the patch dropped. I had a great group of top players. And we literally sprinted through it, working it out as we went. Afterwards I wouldn’t have been able to tell you anything about the run. There was no involvement in the lore, which was amazing considering that these runs were in Ice Crownn for fucks sake. We just blew through it.
I think that the physical act in game of going to a dungeon, grouping up outaide, waiting for other players to come, maybe even asking someone there if they want to come with you, all these things are a deep immersion-style preperation for doing an instance. They make you feel that you are about to go on an adventure. Couple that with the LFG system and you may as well just sit there and play tic tac toe while waiting for 5 players to be found.
So the question is whether in Cataclysm it will be possible to run the new content by finding other players to do it, alla the old style. Or will the hassle of doing this be just so great that your only option be the use of the dungeon finder. I’m not holding my breath, but I’ll give it a try at least.