Can I easily copy or replicate an advanced gradient fill in keynote? Setting up advanced gradient fills is somewhat time consuming. If I'm creating a new shape and I want to apply the same gradient fill as an existing shape, is there any way to copy the gradient fill for the existing shape and quickly apply it to the new shape? 

Copying/pasting the shape is not the answer I'm looking for. Sometimes it's an entirely different shape you want to create, but with the same gradient fill.
Use ⌥+⌘+C to copy style and ⌥+⌘+V to paste style.