This web site seems to be doing a decent job of gathering various statistics from which one can infer popularity:

http://www.langpop.com/

I’d like to believe that C# is the most popular language, but apparently Java ranks higher on most counts. In my opinion many more advances have been made in the .NET platform than the various java based platforms. My guess is much of the popularity is due to the dominance of java when it comes to mobile development (not counting the huge number of Objective-C based apps on the iPhone).

A friend of mine also noted the prevalence of Java in introductory computer science course.

Finally, another friend reminded me of Mark Twain’s quote:

“There are three kinds of lies: lies, damned lies, and statistics.”