Isn't the Shaun Palmer (if they make 'em anymore) honeycomb cores a composite? There have been variations on carbon fiber cores and stuff through out the years. Fact of the matter it's pretty much impossible to beat wood cores for performance. Adding stuff like carbon stringers to the wood core seems to be the way to go.
Oh yea, there are boards with honey comb cores or some type of mixture of it. Yea, wood is best.