One of php's main advantages is the availability of many options. You have the option to do web apps in plain php. You have the option to do web apps in many mature frameworks.

Languages like ruby and python lack this. Can you do a website in plain ruby as easily? How many mature ruby web frameworks are there in ruby? There are many in php. Zend Framework, Agavi, Kohana, CodeIgniter, Prado, Yii, Symfony and many others.

Of course some stuff in php suck hard. I would personally love an string-object to replace all the stupid str_*() functions, but php is in the right direction of adding features. (My last issues are fixed by 5.3's late static bindings)

And im surprised how php community quickly adopts changes. PHP 5.3 breaks compatibility but i see more people using it everyday.

I think despite all the negativity, PHP is going to stay for long-term.