There were some rumors spreading around that there would be no official PHP 4 End Of Life announcement. I have no clue for what such a saying should be good for, PHP 4’s EOL status is obviously history these days. And yes, sure there is an official statement, it was released on July 13th, 2007.
The PHP development team hereby announces that support for PHP 4 will continue until the end of this year only. After 2007-12-31 there will be no more releases of PHP 4.4. We will continue to make critical security fixes available on a case-by-case basis until 2008-08-08. Please use the rest of this year  to make your application suitable to run on PHP 5.
Source: Official PHP 4 end of life announcement on PHP.net; 2007 insertion by me.
The document is still online, so if you run over anyone telling, that there ain’t no announcment, point over there.