I'm not one to rely on WoW Insider (http://www.wowinsider.com) for much. However, with the upcoming changes to our classes and with the release of the new Cataclysm dungeons, I find this to be a very fitting post and one I hope folks will use whether they read this article or not.
Link: http://wow.joystiq.com/2010/10/07/ol-grumpys-guide-to-cataclysm-instance-protocols/ (http://wow.joystiq.com/2010/10/07/ol-grumpys-guide-to-cataclysm-instance-protocols/)
Good read, sounds like classic and BC dungeons. I'm looking forward to using polymorph on a regular basis again - nowadays if I happen to use it in a dungeon it seems to just cause confusion, or the tank will run ahead to the next group thinking everything is dead.