Random Dungeon Finder is a remarkable system. You can earn tons of Emblems of Triumph in very short time, and if you're lucky with the heroics at lv80, you can net even more as each boss drops one in a heroic. But what has this done to the content which I so much love in the game?
It has created even greater separation between the questing and instancing. Or in fact, it has created a gap between the two, a separation which wasn't there earlier.
Formerly, when I levelled up my toons, it was a rare and satisfying instance to get into an instance: usually it was something a quest required you to do. You actively seeked group or company to finish the quest. Now the rewards from the random dungeon overweight the reward from the dungeon quests, and takes away the mysticism of certain dungeons in the game. For example, in our static group we have a warlock, who has been a hardcore alliance player. He had never visited the Ragefire Chasm, not even for the achievement. Now the instance is readily available to both factions and the only difference is the fact that only one faction has quests to it. I guess the same is with the Stockades for the hc Horde players.
The other thing is the fact that it seems that the levelling instances have been made way easier than they were: I had a run with my static group gnome warrior in Wailing Caverns, and at lv18 he was invincible. The group, consisting of levels 17-20 breezed through the whole instance without breaking a sweat, everyone who had been there earlier wondering how much easier it was now than before. The same happened to us in Shadowfang Keep, where the ones who had never been there complained how easy it was.
Yet the rewards and the experience were as they should have been. Plus the bonus sack and extra experience in completing the instances.
There seems to be no real reason to quest anymore, other than just fill in time between getting a new random group. We'll see what happens later on, when we hit the 50-60 range.
Another separation has happened in the level cap in heroics: people are farming the LFD for Emblems of Triumph in such a fervour that they rather plunge through the instance the fastest way possible than kill all the bosses in the instance. For example, the Old Kingdom which I have tanked a couple of times, has been ran at least twice without the two 'side' bosses: instead jumping directly to the end boss. It saves time as you don't have to deal with the unnecessary trash and you can get into another hc as fast as possible without the cooldown.
The separation I mean is the fact that the gear gap between the newly arrived lv80 and the 'geared' is even bigger than it ever has been, and the newcomers are beginning to feel it. I've seen abuse, hear about more and even witnessed some 'wipe-groups' disappear after the first sign of trouble (in this case a tank mostly in blues, but with almost 30k HP and obviously no clue on what he was doing. He was willing to learn, but the healer and dps decided to leave. "L2P, nooob", was the comment...)
So the newcomers are having even more trouble to break through, even though the overall gear level of the playerbase is getting higher and higher. My priest, whom I dual specced as shadow/holy (shadow mostly), is around lv73 now and the gear I'm aiming for before breaking 80 isn't anywhere near the gear I know I need for hc's, let alone anything in the IC.
We'll see what comes out of this. The more the people who have time to run the heroics in the end gain all the gear they can through Emblems and instances, the more people are ready to raid in the Icecrown. Ulduar is already forgotten area, except for the Weekly Raids, and the Trial of the Champion/Crusader is used as a stepping stone if needed for a piece of gear or another.
Even though the LFD opened up the instances to faster grouping and more population, it voided even more of the raid content with completely insocial and anonymous instancing. Why succumb to bothersome arrangements of a raid -which is even harder than the LFD PUGging- when you can get more action and more benefits from anonymous LFD groups?