C now. JavaScript will likely grow in use. Python is also clearly growing, in relative terms. About any other language, I'm not as sure.
what would be interesting is a back of the envelop calculation on # lines of js vs c executed globally per minute. id guss c probably wins due to frequency of execution.
That said, I bet JavaScript use will increase and C will shrink, relatively speaking.
I don't know, I think Excel formulas might still have it beat.