This may not be what you asked for but I'm going to tell you it anyway: as long as you are a good programmer and as long as you can write in at least a couple of modern languages, it doesn't matter very much what language you learn next.

In my experience employers are looking for intelligent people with a good general knowledge and the ability to learn new stuff quickly. A programming language is just a particular type of stuff from this point of view.

Also in my experience: I didn't really know Perl when I applied for a job which required Perl programming. I got the job and I quickly learned Perl.

Executive summary: keep learning all sorts of stuff and sell your intelligence, ability to learn useful things quickly and then to use them in practice.

Paul