Game designer Jonathan LeCraft Tweeted recently that the Fox Kit would be added to the Tol Barad Peninsula vendors in the near future. [source]
Just added the fox kit to some vendors... #wow http://i.imgur.com/2NPxU.jpg
According to the image that was also provided in his Tweet, this pet will require an exalted reputation with either Hellscream's Reach or Baradin's Wardens. It will cost 200 Tol Barad Commendation and be Bind on Pick Up.
In follow-up Tweets, LeCraft mentions that the plan is that this change will go live in the upcoming pre-MoP patch. [source]
Even though the Fox Kit will be added to the Tol Barad Peninsula vendors, the companion will still be obtainable through farming Baradin Foxes. [source]