Currently our map of Azeroth has two continents, but anyone who's played the original RTS games knows more is out there. Blizzplanet has some interesting information that leads me to hazard a guess that we may be seeing more added to the cartography of Azeroth in the future.
They start with the information, lore and such that were added to the World of Warcraft RPG: Lands of Mystery tabletop rulebook. Should you own a copy (I, alas, do not) you will find it contains new info on Northrend and the South Seas . The maps that we saw on the WoW Collector's Edition behind the scenes DVD of Azeroth show that they have been planning such an expansion since 2004. On the map, it shows Northrend at the top of the world, with the Maelstrom and Nazajatar in the middle and the Isle of Kezen/Undermine at the bottom.
Add to this the new novel World of Warcraft: Tides of Darkness due out in August 2007. It seems too much of a marketing coincidence that the novel is planned to come out the same month as Blizzcon. That and the fact that there is an Expansion02 folder with Northrend items stashed in the 2.1 patch due out on Tuesday. It appears that future content will indeed spend more time in Azeroth itself.
It makes sense, really. The developers have been emphasizing that this is one game, not two, and what better way to do this than to refocus their efforts back on the known world. I myself am excited with the prospect of spending more time getting to know the people and places of Azeroth. I love exploring, and have been dying to know what else is out there. Seems like Blizzard will be granting my wish.
[image and info courtesy of Blizzplanet]