The latest version on php.net is "PHP 5.3.1" I think that they are going to be the first to say about php 6. Please give me a link to php6 if you have it.
http://www.ibm.com/developerworks/opensource/library/os-php-future/ http://www.linux-mag.com/cache/7433/1.html
Sorry I have read and saved the article but forget where is the article on my hard disk, rather lazy to find it, maybe you can search google about it
PHP6 will have an more that year to prove that its stable to have a try But while i am in India i tested PHP6 by installing in my Red Hat server seems that its nice but roll backed to PHP 5.3 because of Vulnerabilities and have real time testing for clients
I think it will be some time yet before it is stable and supported by hosts, i'll be interested to see the new features.