While questing through Hyjal today I came across an interesting piece of quest text.
The quest has you collecting fiery cores from fire elementals and destroying them. The Quest giver is referring to a time when players would collect [Fiery Core] to craft fire resistance gear for Molten Core raids.
This is one of my favourite WoW videos of all time.
This was made for a competition on the Discovery Channel where contestants had to make their own versions of the Discovery Channels The World is Just awesome advert. I've inserted the original below as well.