I started with PHP as a teenager, and ended up coding PHP professionally for about 6 years. I'm certainly not sorry for it (:

I haven't touched PHP in a few years (C# and Python for work now) and since really groking a other few languages I've come to the conclusion that, IMO, PHP manages to combine some of the worst aspects of dynamic and static typing to produce an ugly, confused language with gotchas that still haunt me.

But none of that matters - management, directors, clients, whoever care about results and productivity. They don't exist inside of the tech-hype bubble. People want a certain feature set, at a certain cost and within a certain time frame. They certainly won't rewrite their massive code base from PHP to start again in new-shingy-x, when they could be adding more value to an existing solution.

As much as I dislike PHP, I was amazingly productive in it. The systems I developed where way ahead of their competition just because I could iterate so rapidly. (It turns out I am even more productive in Python than I ever was in PHP, hindsight 'eh!)

You mentioned COBOL - there are a world of COBOL jobs out there (this is the first page that came up in Google http://www.jobsite.co.uk/cgi-bin/advsearch?search_type=quick... ) The fact that COBOL hasn't been cool for a few decades doesn't change the fact that there are masses of applications still running it across the world.

In your post you didn't say anything about disliking PHP, you said your scared of yours skills becoming redundant. Don't be - there will be vast amounts of PHP development going on in the world for decades to come, it isn't going anywhere just because the next big thing arrived. It just won't be cool and discussed at length on the internet anymore.

If you focus on being a skilled programmer instead of a coder who only works in PHP then you won't have trouble adapting your skillset. Make a point to really understand how what your developing works and why. When I picked up Java and C# after PHP I was productive in those languages within a few days - they are not that different at all. After a few months you will have learnt the idioms of those ecosystems and be well on your way to being fluent. A great programmer can produce great code in any language, a poor programmer will produce poor code in any language.

I do think it is really valuable to pick up a new language now and again, I always learn something that I take back to whatever I do day-to-day. It sounds like you work in web development at the moment, so maybe stick with something along those lines. Expert Javascript developers are so hard to find, I always find them the hardest to recruit for! It is a challenging language - everyone seems to 'know' it at some superficial level, but make an effort to really understand its idiosyncrasies.

Much more important than anything I've said above - developers have very personal, often very strong, opinions about programming languages. Take them all with a pinch of salt - programming languages don't matter nearly as much as we think they do. Play with a bunch of languages and then focus on a few the few that you really take to - quickly you will find something that you are passionate about enough to want to put your next 10,000 hours into.