The whole argument always amuses me everytime it comes up. It's always made out that the speed running tanks are the bane of all existence. However, every dungeon I've gone into since I started tanking in 2.1 I open the dungeon with "Hello, do you all want big or small pulls." Almost universally, the answer is always nothing or that they want big pulls (3 times in a year and a half, I've been told to go slow).

As far as DPS pulling additional mobs, you should welcome the challenge. Yes as one poster stated there are no endgame mechanics where DPS/healers have to run ahead and pull mobs but there is a veritable ton of endgame mechanics where adds pop and you need to know how to secure snap aggro. Can it be annoying? Maybe if they're doing it too much but if that's the case maybe the tank should push a bit harder. If the party wipes because the DPS pulled additional mobs, then who cares? It's not like wiping has huge consequences. If the DPS get uppity, then you can point out that they were the ones who pulled more than you can handle and you can send your smugness through the roof!