If you are under any doubt about Facebook steering the future of PHP, have a listen to this interview with Sara Golemon of Facebook on The Changelog:

Facebook's Sara Golemon and the PHP Language Specification

Topics covered include the HHVM runtime from Facebook, their Hack language, and more importantly the effort to design a specification for PHP itself (yes that currently is been driven by Facebook).

I admire what Facebook are doing with PHP, but I also have concerns given that they are ultimately motivated by their commercial interests.