wow, this brings back memories for me.
I was at a forum a few days ago, and a came across a certain video, which brought back a lot of memories for me as a someone who has played on quite a few MUDs in the past. Even though this video is from the World or Warcraft, it made me remember all the foolish, idiotic players I had grouped with in the past. Of course, most of these people's idiocy aren't broadcast for the rest of the world to see and enjoy.
Basically, the cliffnotes for this little episode is a group called Pals for Life made themselves a little movie(which I assume was a preplanned stunt and not a spontaneous moment of gameplay), in which one of their members named Leeroy just decided he was going to go it alone into a very dangerous room... which caused the rest of the party to follow him in and bad things naturally happened after that. I think it is safe to say that every person who has ever played a group-related game online, whether it be UT or Counterstrike to the most extreme MMORPG has played with at least one person who just up and breaks with the plan that is being set out wth disasterous consequences for the group as a whole. And if you haven't, then you probably are that person.
And I think that is why this video has been striking such a chord with people outside of WoW... the humor of the situation transcends the game it is happening in. I've seen it on Star Wars Galaxies, Day of Defeat, Ultima Online, UT forums along with a few major gaming news sites... and basically the chorus is the same... they've all played with a person like that, so they sympathize with the situation.
The aforementioned incident had such an impact that the term "Leeroy" has become quite the object of speculation on the Urban Dictionary. I don't know if it really is going to take off, because calling people variations of the term "smacktard" is still the standard operating procedure, but I have a feeling if the term doesn't last, people will probably find themselves telling each other about videos like this for a long time.
And there are probably going to be spinoffs, parodies and copycats soon... so the joke will go on.