At one user group meeting, recruiters said that companies are asking for so-called Super Developer, who can use e.g. Java, PHP as needed.
At that time, I thought that it is difficult to be such a developer unless you are in an Agile software development environment, especially, Extreme Programming using Pair Programming.
In Extreme Programming, developers work on different tasks, e.g. front-end, server-side, database, environment settings, switching to work on different tasks often. But if you work in non-Agile environment, you are only assigned to one task, such as front-end GUI development and you never have a chance to even look at the code for the rest of the system.
One recruiter said that you need to be able to work on both Agile and non-Agile environment. Of course, she is just a recruiter and doesn't know what is actually involved in software development. But you can't ask a developer to be a Super Developer while you are demanding him/her to work in non-Agile environment.
Also, I thought that they are missing that each language has its pitfalls. How can one person know the pitfalls when he/she is working on many languages for a short period of time each? What I observed from those developers is that they tended to use wrong solution for each language because they didn't know that there is a better proper well-established solution in a particular language because he/she hadn't had enough time to learn about them.
I also think that it may be an organizational problem in the companies that they demand Super Developer. Aren't they using improper stale technologies instead of improving to use better technologies that have learned from the mistakes made by other technologies in the past? If that's the case, even if the companies bring Super Developer, he/she cannot solve the fundamental problem and as he/she works in such an environment, he/she eventually stops being Super Developer because he/she is constrained to use only the technologies the companies force.
Instead, I agree with what Scott W. Ambler said in his essay on Generalizing Specialists.