In any case the DirectCU II cooler should make quite a difference. Asus has plenty of experience and it has shipped the DirectCU II cooler on countless Radeon and Geforce cards, so performance should not be an issue.
It features two fans, but one of the fans also has a small blower that it supposed to channel air toward the rear exhaust vent. It uses massive 10mm nickel plated heatpipes in direct contact with the Hawaii GPU.
Of course, since this is just a tease, Asus did not reveal any specs. Asus does promise a consistent level of performance, lower temperatures and less noise – but that sort of applies to all custom coolers out there.