Nanotubes versus copper

Can nanotubes replace the copper fins that are attached to silicon chips for cooling purposes? Researchers have found that the nanotubes dissipate heat at the same rate as copper. The advantage is that the nanotubes are 10 times lighter, stronger and more flexible. If the price is right, great but I have a feeling that the costs could be a real turn off. Besides, how much of the weight say in a portable gadget like a mobile phone is made up of copper fins? The weight saving may well be imperceptible. Here is the reference for those who are interested (Appl. Phys. Lett. 90 123105).