It is nice to have an impression in which programming language others write their programs.
TIOBE publishes a comparison on how popular a language is in the community (based on Google, MSN, Yahoo!, and YouTube searches)
Hopefully there will be (some day) more informations about that. E.g. how many projects registered on sourceforge, freshmeat, (not javaforge of course) etc. used a specific language and how much lines were written for these projects. This would be interesting. But of course every language has its pros and cons…
Although you can see a slightly decrease (except for C#) of the major languages like Java, C++ and C. Scripting languages have gain and will gain more importance – if hardware performance and number of available libraries will increase.