I've written code in Java, C++, C, PL/1, Pascal, Wang VS Assembler (clone of IBM 360/370 assembler), Fortran, and Basic. And I'm sure I'll learn new languages soon, because, like many others, I'm sensing that Java's reign is waning.
I'm obviously not a compiler engineer, because when I look back at the code I've written, I don't really focus on what language it was written in, but what the program did, and how it made people's lives better in some small way. I can't really say I prefer any of the above languages, except maybe they're all faster than Assembler, as that could get tedious (though the tedium was sometimes rewarded by being able to do something with particular Yankee efficiency).
I get frustrated when reviewing resumes with people who say that the candidate "must have" Java. I'd far prefer a C programmer who writes clear and beautiful code than someone who knows Java maybe a bit too well and is focused on playing silly language tricks that obfuscate the code. Just as in human languages, it doesn't matter what language is being used to express the thought, it's the thought that matters. And in engineering, clear and simple thought yields (in my opinion) the best code.
I didn't always feel this way. Is it cynicism? I don't think so, but maybe. I used to worry that I'd be out of date, unmarketable if I didn't make the jump from PL/1 to C, and the other language transitions after that.
Or maybe it's just evidence of the subspecialties in software engineering. Some English majors specialize in linguistics; others in literature. I'm glad the linguists are out there, because someone needs to make sure these languages parse and make sense. If I have to learn a new language soon, ok, bring it on. But until then, I prefer the literature :-)