From WoW: IncGamers World of Warcraft Wiki
Introduction
Utgarde Keep is a dungeon in the up-coming expansion Wrath of the Lich King, planned for release sometime in 2008
The serene trip by boat into Daggercap Bay stands in sharp contrast to the scene at your final destination, the besieged town of Valgarde. As the boat comes to a stop at last, you find yourself in a town under siege. Enraged vrykul charge the town’s defenders, overwhelming them with their sheer size and savagery. Buildings catch fire and burn before your eyes, and the cries of battle mingle with the shrieks of the proto-dragons flying low overhead. Despite the chaos, your eyes are drawn to the massive stone edifice dominating your view -- Utgarde. As you gaze upon the twin skull visages on the façade that leer out upon Daggercap Bay, you feel a shiver run down your spine that has nothing to do with the frosty air.... - Blizzard
Utgarde Keep contains three dungeons: Utgarde Catacombs will be the first dungeon that players who arrive in Northrend will attempt. Located in Howling Fjord, the fortress looms over the vista from its lofty position, built into the side of a immense mountain. Utgarde Pinnacle will be a 5 man dungeon for level 80 players and there will also be a 25 man raid contained in Utgarde Keep.