Right all wrong – we all seem to have this < 2k dps in a Northrend Dungeon and you fail – which for the most is true.
Sometimes I struggle to reach that when I am running in a overgeared group when stuff just dies so quick.
Most of my circumstantial rotations start with dots – If there is enough time for me to stick dots up, maybe some mindsearing, and single target then I am going to do awesome on actually dps measurement, and either come 1st or 2nd in the party , but well geared Aoe tanks – and 1 or 2 burst Dps in the party, and I’m last.
So the real dps measurement when stuff is dying quick is not how much damage I can actually do, but how much damage I can beat other classes to doing. Eg I’m more likely to stick one dot on them, Shadow Word Death / Mindblast on cool down, and mindsear where practical. No point sticking dots on them if they are taking 5 seconds to die.
In addition In a 5 man – helping the party rather than yourself reduces your Dps. If the boss is dying fast – and your party member has just been iceblocked. Leave him, boss will die soon anyway, and besides, its less dps being done by that party member = more for you to do.
Same with dispels – If you have a healer who can’t dispel something because of their class – how many people will dispel rather than keep on dpsing.
I think the speed that a Random can be run is creating lazy players. No wonder tanks are struggling for agro sometimes when the Dps are having Peeing competitions for top position. The sad thing is with fully over geared groups – because the healer and tank are op too – the healer can heal the dps through most stuff, and the tank just works a little harder. So sometimes maybe only the Mage dies – gets rezzed and they do it all again.
Provided by 
Pugnacious Priest's Warcraft Blog 
I understand what you mean about thing dying too quickly. My main is a Hunter and sometimes when in a party that is heavily better geared than I am, I send my pet in and start to shoot and the mob is dead before the cat or my arrow even reach it. It is frustrating and sometimes I just want to just put myself on follow and smash things in the room. But instead I grit my teeth and promise myself to get better gear… someday.
~Kai (Meja from SaN)~
2 points.
Firstly as a holy priest I usually pop a renew on tank then start smiting mobs. On the rare ocassion I might need to hit circle if there is some aoe dmg. I might try healing in shadow spec for ilvl200 instances and leave the healing spec for ToC5 and the ICC 5’s.
Secondly I recently swap my Druid from cat to bear and it seems I may have been missing an important fact when yelling at tanks to slow down. With heroics now being chores rather than enjoyment and DPS classes aiming to be top dog, I now move onto the next mob before the last dies so I can get a threat lead before the overgeard DK or ret pally get there.
Maybe the solution is for the the tank and healer to get together and set the pace rather than arguing with each other. If DPS doesn’t like if you can always just use 2, or grab another from the endless LFG queue .
I can sympathize. My alt is a warlock — an Affliction warlock. If I slap on the dots as per my usual rotation, everything’s dead before I’ve finished casting my first Shadowbolt. If it’s a pack and I start throwing Seed of Corruption — half the stuff’s dead before I can apply it a second time. At least I can usually look halfway competent on bosses (or in the ICC-5 heroics), though some of those have been going down in 25 seconds lately, too.
Oh well, when Cataclysm hits we’ll be back to square one.