IEEE — the world's largest professional association for the language of technology — recently published its ranking of the popularity of programming languages. The R language comes in at number 9 in the list.
The ranking is based on 12 weighted factors, including Google search rankings and trends, social media chatter, aggregator posts (Reddit and Hacker news), social programming activity (GitHub and StackOverflow), job opportunities (Career Builder and Dice) and academic citations. Looking at other statisics/analytics languages, Matlab was ranked #10 and SAS at #32. Python, a general-purpose language with some analytics capabilities, ranked #4.
You can explore the rankings, or even create your own rankings using factor weightings different from those used by the IEEE, at the link below.
IEEE Spectrum: Interactive: The Top Programming Languages