The Howling Oak, located in the night elf capital of Darnassus, is the new home of the Greymane worgen after the fall of Gilneas. It is dominated by a "worgen tree" very similar to Tal'doren in the Blackwald. For a short time Genn Greymane is present here after the worgen starting zone. It would seem that Gwen Armstead is holding the fort down while Genn is in Stormwind with Varian.
All Gilnean trainers from the Gilneas starting zone are present here other than the druid trainer who has moved to Stormwind. You may also see other people from Gilneas here including named and unnamed NPCs.