LOL, Mountain Dew is one of the most popular drinks with Cast Members. You find all sorts of pepsi products in the cast fridges. I used to poke fun at people carrying around a Dew bottle or wearing a Dew tshirt. I was always like "it's the forbidden drink of Disney".
At one time, long long ago, pepsi and coke used to be sold together at Disney, then coke realized a huge profit maker of being the sole product and created a contract with Disney over it. Pepsi used to be the original sponsers of the Country Bear Jamboree and the Mile Long Bar.
Although I do love the fact that Sea World serves Pepsi, and refills are only a buck with their cups.