There is a bit of story sprinkled into the region as the trolls in their huge temples are trying to call down the spider goddess, Shadra, and that's about the most interesting the region gets.
Along the way you do a lot of random killing and fetching for the locals and that's about it. The basic story in the Hinterlands is about trolls, especially if you're Horde as you align yourself with the Revantusk trolls as well as a group of Forsaken who are both battling the Vilebranch trolls. Although the revamp of the zone does improve its accessibility and flow, like the Highlands before it, it doesn't really have an interesting story or memorable moments and proves to be a rather dry experience. The Hinterlands was particularly less visited before the Shattering as those questing in the Eastern Kingdoms would get breadcrumb quests down to Stranglethorn Vale after completing Arathi Highlands, so it's a zone that I had little experience with, except during holidays when I would run up there to take care of whatever meaningless tasks I needed for the achievements. The Hinterlands lies just north of the Arathi Highlands and is the next area that Eastern Kingdoms questers will encounter.