That is true with that prototype, the low pressure "heat pipes" that are used in cheap heatsinks~less than 100 dollar heatsinks etc. The heat pipes setups couldnt pump up with hardly 1 G of force to deal with. Decent, professional level heat pipes can deal with over 10 g's of gravity and perform much better. I think that is what they may be waiting for, and to be able to get it cheap enough also. The heat pipe slk800 was a prototype so it was sort of rough....not all shiny and such. And yes you still would need airflow over any heatsink~large copper plate thing etc, just hopfully less cfm~more effecient and less noise to get good enough results. Convection on some stuff could be feasible if effecient~large enough etc. But even that needs airflow, as otherwise it would still cook, just slowly.