C language is the most important language for EE's.
Apart from that, it's the second most used language in the world. Only Java is more popular.
I'm not sure 'popular' is the right word for Java. Java is used in cell phones and there are a bunch of phones. As a result, Java is probably the most 'executed' language, perhaps not the language with the most programmers. I think we get into a semantic battle when discussing the 'popularity' of Java.
In terms of application programming, I would expect C++ to be the most used (have the most programmers). I imagine C# will become important and when I want a widget in a hurry, Visual Basic is the way to get it built.
In the end, a language is just a methodology for expressing an idea. It's the idea that's important, not the implementation. Sure, the implementation gets all the accolades but almost every idea can be programmed in almost every language.
Bottom line: Learn to express the ideas and worry less about the language. Your employer is going to tell you what language to use. Therefore, you need to know all of the top languages (C, C++, Java, Python) and it wouldn't hurt to know the second tier as well (Fortran, Pascal, Perl, Ruby, Rust, Visual {Basic, C++, #}, <whatever>).
For the practicing EE, I still expect C to be the most important tool in the toolbox.