When Warcraft launched back in November 2004, my Everquest guild decided to roll characters on an RP server. Not because we wanted to RP, but we hoped the maturity level would be higher. One of the pleasant side effects of this decision is occasionally stumbling across RP events by accident.
This mostly happened in Stormwind before the expansion. On the way to the flight master, I would pass two characters sitting in a boat by the canal professing sorrow at how the unending war had kept them apart for so long. Or when I stepped into an Inn to unload my grey loot and pick up more drink, I would spy a group of players in peasant clothing exchanging wild tales of heroism and foolishness.
While my RP interactions are accidental, I found a great resource for those who enjoy the Role Playing aspect of the game: The WoW RP Wiki. It's free to register if you want to contribute. I've dug around and found some great Stories in there such as the Equal Rights for Equal Heights gnome march on Ironforge (complete with video goodness) and the memorable Curse of the Ogre Loincloth.
Check it out if you are looking for a new RP resource or if you are looking for entertaining Warcraft fan fiction to pass the time.