Here are the specs, I'll include the Founders Edition for reference:
The flagship is the GeForce GTX 1080 Ti FTW3, there's still no photo of the final product so it seems this model will launch after the other models. Here's the render that was revealed a couple of weeks ago.GTX 1080 Ti Founders Edition: 1480MHz base clock, 1582MHz Boost, 11000MHz memory
GTX 1080 Ti SC: 1556MHz base clock, 1670MHz Boost, 11000MHz memory, dual-fan iCX cooler
GTX 1080 Ti SC2: 1556MHz base clock, 1670MHz Boost, 11000MHz memory, dual-fan iCX cooler, extra features like iCX temperature sensors vs the regular SC model
GTX 1080 Ti FTW3: 1569MHz base clock, 1683MHz Boost, 11000MHz memory, triple-fan iCX cooler