The bitch is back, everyone! Hills fans are anticipating the return of Laguna Beach alumni Kristin Cavallari, as the fiery blonde makes her debut on the hit show this season. Not only will Kristin be appearing on The Hills – she’ll be a regular and she’ll be filling the top spot, previously held by her arch enemy Lauren Conrad. MTV released a sneak peak video of Season 6, teasing fans with clips of Kristin and Justin Bobbi