The renowned Michael Whelan--the cover artist of The Way of Kings and many other fantasy covers, such as the cover for A Memory of Light--will return to do the cover for the second Stormlight novel, Words of Radiance. Tor announced the news earlier today.
It was never a sure thing that Whelan would return, as he is incredibly busy. But Whelan wrote some initial thoughts on Words of Radiance, and it seems Whelan was suitably impressed once again:
So well, if you weren't excited for Words of Radiance already, you should be, clearly.