I think Skulls can be a kind of money in dow3. What could be cool, and good for the community, could be to have "skull prize".
I explain, i think that relic could deliver some code to offer skulls. It will help to do a present to the players during a stream. It is diffrent from a serail key number to have the game. But if Relic intends to sell some skins only with skull or XP, it will be an easy way to thanks some of the streamers or players.
Imagine : You damned want this hero skin .... Ok it will be yours for 2000 skulls. Pretty hard to get isn't it? But come on my stream at this time and you will have a chance to win 3 times 1000 skulls!
After, if relic wants to use the classical way "pay 10$ for 1000 skulls", it could be a way too. And as Blizzard with the warchest : 25% goes to support esport! With that, they will show their interest on all side of the community : casual players, that want skins, and more proplayers that alwayz wonder if DoW3 is really supported for esport.
With that way, they can continue to develop the game, prepare new races, new campaign etc etc. Skins will be just a way to earn money for them, and animate all streaming sessions. And Skins seem to suit to a lot of the nowdays players. I don't really care about them, myself, but it is a cool option.