Considering all the media coverage listed at the end, I'd say the copper foam was an effective marketing gimmick, enough to have actually funded the project were they not frozen. After that they could have run with the money or tried to implement it. If they had tried to implement it they would have eventually fallen back to reference boards or commodity parts in a slightly larger size, and probably just had the hardware clock down when overheated due to the badly designed heat sink, so I think they could have delivered. There are successful companies out there that rely on marketing gimmicks, like Bose.
I'm not convinced that copper foam is a good idea for a heat sink, but this article doesn't give enough detail to convince me that it's a bad idea either.<p>The radiative emissivity might be a bit of a red herring, since heat sinks typically rely more on conduction and convection than on radiation for cooling. So then it comes down to some hand waving about boundary layers.