WOW MOROV YOU TOTALLY TOTALLY TOTALLY STOLE MY IDEA I WAS GONNA POST THIS
On a serious note, if you can get past his accent and strange pronunciations Nobbel is THE guy to go to to learn about the Lore in WoW. The story is MASSIVE, with events ranging from the creation of the Universe, to the Sundering, to the Present day. The story is one of my favorite things about the game and knowing what's going on and the history of the areas you go (ESPECIALLY COME LEGION OMG THE TOMB OF SARGERAS) adds that much more. Also, knowing the history of some of the artifact weapons (Ashbringer, Doomhammer, etc) will make it that much more special when you get a hold of it.
I highly recommend playing through Warcraft III and WCIII: The Frozen Throne if you're a fan of RTS games. The events in that game are the most recent before Vanilla WoW and help to set up the relationships between some characters. That doesn't mean stuff gets shaken up, specifically in Cataclysm and Mists of Pandaria content, but it'd be a start.
At the very least, take the time out to watch the history video.