http://www.indeed.com/jobtrends?q=java%2C+c%2B%2B%2C+ruby%2C...
edit: fixed spelling of clojure ;)
Stackoverflow/web searches over-represent languages used with the web (esp Javascript). But, since the web is the fastest-growing industry, it may be an accurate anticipation.
That said, I've wondered for a long time if the Tiobe index is subject to a potentially much bigger source of skew - namely, I suspect that C, C++ , and Java get a boost for being three of the most popular languages for people who spend more time talking about programming than actually programming.
TIOBE seems weighted towards blog/article writers, using GitHub et al. would be weighted towards the open-source community.. Stack Overflow is also a fairly cohesive community, though a harder one to name: people who ask for help in online Q/A sites?
For instance, I'll bet that none of those three communities overlaps much with government contractors. Within the firms I've worked with, they are very, very hesitant to even use the Internet, let alone participate in it. Information comes from dead trees only. They are also staffed by a much older crowd. And they have a ton of software developers keeping Ada, C, Assembly, and Forth alive and kicking.
