I've only ever played the WoW trial, but one thing I've seen people do on youtube videos that is technically an exploit is kiting. This is when players use weak attacks on a large boss to make them follow them without taking too much damage, eventually arriving in a city and watching the boss kill all the noob players.
I can just imagine getting attacked by one dragon, and while in a chase two more come after you, and then you take them to a large settlement and they cause hell >=) this was possible in Oblivion, but it would be hilarious to set bigger, badder bosses like dragons, giants, and ice wraiths on all the poor villagers