Looking at http://images.content.ubmtechelectronics.com/Web/UBMTechElec..., I can see where that argument comes from. Looking solely at the C++ data across the years, slides 20 and 21 can be seen as indicators that C++ peaked in 2011. If that's the case, however, C peaked in 2012.
Also, for C, there seem to be fewer 'next' projects than 'current' projects, while for C++ those numbers are about equal.
Extrapolating like mad on almost no data, one could argue that C is on the way out in favour of Python, Java, and C#.
.Net is on the decline, though, so there either must be tremendous growth in the use of Mono in embedded software, or that data must be taken with a grain of salt. My money is on the latter, but surprise me.
Some time ago there was a shift towards c++,but a large percent are returning back to c.
That's what i recall from surveys from UBM, the company that runs eetimes.com .