Not being a PHP Developer (but being an ex C/C++ developer for over 10 years), just a documenter/supporter/evangelist of Drupal which is a PHP website/webapp development framework whose core is very clean according to developers I respect, I can tell you that it's all about the apps!
Where is the flickr (flickr is mostly PHP with 10% Java and a bit of DHTML and flash) of Java? Where are the Drupal and Joomla and WordPress (just to cite content management) of Java? Java's great for enterprise apps developed in house which makes a lot of money for Java people now but in the areas I care about: web applications and applications that I run on my personal desktop, Java is dead.
It would have been impossible to (just to cite a few Vancouver based examples) for NowPublic, Project Opus, and Rental Monster to have been done in Java with the limited resources that they were started with. Java is just too heavyweight and hardware intensive and just not suited to incremental iterative development
Bold Prediction: key web apps and the next Microsoft, Google and Yahoo will continue to come out of PHP and its brethren of Python, Ruby, and Perl, not Java.
Bold assertion: flickrTime development is impossible in Java.
Finally, it's not a war or about vulnerability, it's about providing the coolest, most usable software to real people; and Java has failed miserably at that (maybe it'll happen on mobile phones but I am not holding my breath) and there is no sign of it starting to succeed.
From On PHP.:
Everyone agrees on PHP's upsides: it's written for the web, it's easy to deploy and get running, and it's pretty fast. Those are important advantages. And I'm sure that it's possible to write clean, comprehensible, maintainable, PHP; only apparently it's real easy not to. But PHP has competition, most obviously Rails; and don't write the Java EE crowd off, they're not stupid at all and they're trying to learn the lessons that PHP is trying to teach. So PHP has earned everyone's respect by getting where it is, and Sun should reach out to it more than we have. But in the big picture, it feels vulnerable to me.