Languages or technologies only die when they don't adapt or are not cut out for a newer, gearter demand task. Look at C++ it's still going strong, unlike Pascal and others like it.
Sometimes, the best language doesn't even win. Personally there were some features about Pascal I really liked, it was a very structured, clean language, yet more people stuck with C++.
PHP is not going anywhere soon...too much code...to much legacy...like C/C++ applications will not be ported to MC++ over night...
I think keeping the community centered around PHP or rather the LAMP stack is best...otherwise communities get bloated and grow out of control. I don't like Sitepoint because it tries to hard to be to much...
Ruby and Rails I think are a fad...new technology to experiment with "real" agile development and XP. That accounts for a small number of developers world wide. Most programmers care less about TDD/BDD or even writing good code, just look at open source projects.
Python is like the object oriented replacement for Perl...I see it no where except in Trac...everything else is PHP baby.
Java will continue it's battle for supremacy in the mobile market...C/C++ will continue to dominate in both Linux and Windows desktop development...PHP will reign king as web development environment (building dynamic web pages mostly) Perl will die a slow painful death cause of all the legacy scripts probably floating aorund for *nix. Python is a good experimental language when your tired of the procedural techniques of Perl.
Yup...PHP ain't going no where's my friend. Saying it'll be shadowed by Ruby or Python or ASP is like suggesting Shell scripting will replace Lisp.