WOW - One Expansion Per Year : World of Warcraft General Discussions

A while back Blizzard stated that they were aiming for one World of Warcraft expansion per year. Of course no one knows how literal to take this and Bornakk continues to tease with this partial answer:

This is something we talked about awhile ago and it is still a goal for us. Keep in mind that a goal isn't a guarantee. We are always trying to add as many dungeons, items, and features as possible and this of course takes time. So when will we release Wrath of the Lich King? When it's ready.

See the full post here.

http://forums.worldofwarcraft.com/threa ... 0012&sid=1