HPC is dying, and MPI is killing it
Yes, "high performance computing" is dying. There's no commercial market for it. Check the list of the top 500 supercomputers in the world.[1]  The top 10 are all Government operations.  In the top 25, there are a few oil companies, mostly running big arrays of Intel Xeons.CPU clock speeds maxed out between 3-4GHz a decade ago.  Nobody develops special supercomputing CPUs any more. The market is tiny. Old supercomputer guys reminisce about the glory days when IBM, Cray, Control Data, and UNIVAC devoted their best R&D efforts to supercomputers. That ended 30 years ago.Supercomputers have poor price-performance. Grosch's Law [2] stopped working a long time ago. Maximum price/performance today is achieved with racks of midrange CPUs, which is why that's what every commercial data center has.  Now everybody has to deal with clusters of machines.  So cluster interconnection has become mainstream, not the province of supercomputing.[1] http://www.top500.org/list/2014/11/
[2] http://en.wikipedia.org/wiki/Grosch%27s_law