So I have been able to level my pally to 47 over the weekend, doing ZF twice and ST 3 times. Ive also leveled my shaman to level 27 from 23. Doing 80-130 DPS at level 27 is pretty nice as Elemental. Doing all these dungeons, ive only had 1 or 2 good groups. most of all my bad experiences have been in Gnomeregan, someone in the group has to leave for some reason, and deciding to be annoying he pulls about 30 mobs then leaves group, leaving all of us to die one by one and run back in to the instance, almost always we lose some members along the way. Theres also those people who have no clue what their doing, Druid tanks in kitty from, pally tanks without righteous fury on, and Warrior tanks tanking 1 single mob and nothing but that mob. Theres also the healers, who seem to always just heal the tank and no one else in the group because "I didnt know you were taking damage..." and "i'll go oom if i heal the whole group." Finally the DPS, you shouldnt be doing 10 dps at level 20 something... My shaman totems do more than that.
Even though theres all of these negatives, I have stopped the lengthy questing and spent my time in Major cities right by the class trainer and just queueing away in LFG. The DPS seem to be having the hardest time finding groups. This will probably even out what spec people choose to level with. You will see more people leveling with a tanking spec or healing spec now mainly for quicker queues on LFG.