Check out this item on eWeek: Java, C, C++: Top Programming Languages for 2011 - Application Development - News & Reviews - eWeek.com.
The presentation starts with Java, C, C++, C# -- not surprising. These are clearly the most popular programming languages. These seem to be the first choice made by many organizations.
In some cases, it's also the last choice. Many places are simply "All C#" or "All Java" without any further thought. This parallels the "All COBOL" mentality that was so pervasive when I started my career. The "All Singing-All Dancing-All One Language" folks find the most shattering disruptions when their business is eclipsed by competitors with language and platform as a technical edge.
Weirdly, Perl is 6th. I say weirdly because the TIOBE Programming Community Index puts Perl much further down the popularity list.
PHP is next. Not surprising.
Visual Basic weighs in above Python. Being above Python is less weird than seeing Perl in 6th place. This position is closer to the TIOBE index. It is distressing to think that VB is still so wildly popular. I'm not sure what VB's strong suit is. C# seems to have every possible advantage over VB. Yet, there it is.
Python and Ruby are the next two. Again, this is more-or-less in the order I expected to see them. This is is the second tier of languages: really popular, but not in the same league as Java or one of the innumerable C variants.
After this, they list Objective-C as number 11. This language is tied to Apple's iOS and MacOS platforms, so it's popularity (like C# and VB) is driven in part by platform popularity.
Now we're into interesting -- "perhaps I should learn this next" -- languages: Groovy, Go, Scala, Erlang, Clojure and F#. Notable by their absence are Haskell, Lua and Lisp. These seem like languages to learn in order to grab the good ideas that make them both popular and distinctive from Java or Python.