As part of an interview Warcry did with Jeff Kaplan, Jeff was asked…
WarCry: Much of the Horde experience in Outland revolved around the history of the orcs and the Mag’har tribe. What races can we expect to find tied to the lands of Northrend?
Jeffrey Kaplan: Northrend has some great story development in it. Humans, dwarves, tauren, and trolls will all have their storylines developed further. Of course, all of the other races will share the spotlight as well, but those four have an especially strong presence throughout the icy continent.
The rest of the article can be found here.