WAY TO is often used as an expression of approval or a compliment. The most common is WAY TO GO. IF you look this up, it should give you a better understanding.
WAY TO THROW A PARTY; Way to bake a cake! Way to ace that exam!
So, "Way to state the obvious," is a sarcastic way (i.e. a compliment that's not really a compliment) of telling someone they are saying something that is obvious.