Atlanta boardgame warehouse is selling this seperately, and white dragon enterprises had one for sale a few days ago well. They also sell the base game, but they don't state clearly that they don't include the promo tile, I hope there won't be unpleasant surprises for their buyers!
I bought snow tails at my FLGS yesterday, with the leap of death tile of course. I told him about the stories I read here that some distributors hold back the promo tile and then perhaps sell it on ebay.
But the shop owner told me that sometimes distributors hold back on the promo items because they don't trust the shop owners. Now I can see why!