The Idea behind the prophets is to get the floatation of a snowboard, The Prophets are 130mm in the waist which is 13cm, a snowboard thats fairly wide is around 26cm in the waste, and you have two skis and one snowboard. That equals the surface are of a snowboard, and a little more cause skis are longer and the sidecut of four edges instead of two.
I think the idea is feasable, just not to the majority of skiers. I think they should sell some to the public though, cause i would like to try them, and im sure many others would too.