The tallest of the races, the norn revere the spirits of the wild, and are capable of shifting into a half-animal form. A proud, solitary race, they live or die on their own merits. However, they will often enjoy each other's company on a hunt, telling tales around a fire, or having a grand alemoot (at which they get drunk and tell tales). Norn believe they become immortal through having their stories told through generations, so they will often undertake great quests in an attempt to build their legend.
The norn are another race we first encountered in the Eye of the North expansion. Living in previously unexplored mountain lands north of the shiverpeaks, the norn are willing to help with the destroyer threat once we convince them that it would be a hunt worthy of a norn.
250 years later, the rise of Jormag has forced the norn from their homes. They've since rebuilt elsewhere and have an alliance of mutual respect with the charr. The norn won't be knocked down easily though, and fighting the great dragons and their minions is the stuff legends are made of.
A group of norn known as the sons of svanir have decided that instead of fighting the dragons, they should be respected as new spirits. They seek the power of the dragons for themselves, though they are ultimately corrupted by it. The other norn are often wary of these members, but since norn treat others based on their actions, they are generally tolerated in society.
I'm still torn on the norn. Animal form is an interesting mechanic, but I'm not sure I want to be so very tall. Also, my tendency to hide from notice is in stark contrast to the norn's quest for fame. Maybe it would be good for me.
Read more about the norn on guildwars2.com's norn page.