The story doesn't end on each patch.
As Venziir said, Western Plaguelands and Koltira being sent to Undercity.
Permited the beachhead on Twilight Highlands.
The goblins don't have a faction identity? O_o
The Worgen is a brand new race, that didn't had the time to build up differently from the humans or the night elves.
The story is there (and these are only few examples, there are many more), you simply choose not to care about it.
---------- Post added 2011-05-21 at 11:38 AM ----------
Three, actually, the fourth is Leyara.