Well, I don't know what you really mean by "future proof". JavaScript will probably remain the lowest common denominator, for years to come, so from that perspective, there's no safer bet.
However, for people who want to have an edge, as developers, working in their language of choice is one sure way to get it.
There are many different developments to make that happen, like languages that compile to JavaScript, or binaries that run in the browser via NaCL; I think there's a lot of potential there.
... JavaScript was not a language designed with software engineering in mind; that much should be clear. If you can choose the proper language for the task at hand, instead of simply being forced into JS, you'll be ahead.
Companies should also be very clear about what they're actually looking for. If you're looking for "world class" talent, don't complain about a "programmer shortage".
The fact that there were 600 valid applications (the women applying had code examples to show), basically busts the "programmer shortage" myth.
There are a whole lot of people who can program computers, and who could, with some investment, become valuable assets.
> It'd be fascinating to know what they're working on now.
They're almost certainly not working with technology that's "ahead by 10 years", as their recruiters like to advertise: Their hardware is basically standard stuff shipped by Sun (... I guess that's Oracle now), running mostly Java.
4 spaces I can somewhat understand, but 2 ... ?