*** New Since Writing This ***
PHP has now officially been released as can be seen on the PHP news page.
The release of PHP 5.5 is imminent now. The source code now appears to be getting merged on the official PHP github repository. The news file (which highlights a lot of the new features and fixes) can be found at https://github.com/php/php-src/blob/php-5.5.0/NEWS. I am particularly looking forward to using the new password functionality as well as being able to use the FINALLY keyword.
Along with the release of PHP 5.5 this will begin the end of life process for PHP 5.3. The issue is already being discussed on the PHP internals list.
As you can see the current plan is that once 5.3.27 is release in a few weeks the only updates to the 5.3 branch will be security only fixes (and there doesn’t appear to be any opposition to this). Johannes Schluter has posted a new blog post about what you can do from here if you are using PHP 5.3 and can be found here.
Now really is a good time to be looking at upgrading PHP. Preferably you should be looking at upgrading to 5.5.
A good video to help explain the new release and update cycle for PHP can be found on youtube (this subject starts at 3:14):