To my knowledge such huge high performing machines make their ways in the research laboratories where their main usage in simulating the atmospheric systems such as the world weather studies or modelling the phenomenon about the stars being formed and so on. For such simulations and modelling the more computing power the better. The benefits of such simulation cannot be really measured in the commercial terms but I am sure the govt funded R & D institutions are ready to pay for such supercomputers.
I don't think MIC is costing Intel much. yes, they have research groups that occasionally spin custom chips, but that by itself isn't a big expenditure. it's a little hard to tell, but Intel seems to have been pushing the same current rev of MIC for several years now, and it wasn't anything extreme when originally released.
most of the action will be software anyway.
These huge computing systems obviously cost a lot, but do they really make money? Seems the number of sales will never pay back the R&D. I'd be interested if they are a kind of live research lab for technology that will trickle down into the marketplace where the real profits lie?