Biggest change?
- Drop Windows XP and 2003 support
* PHP is getting the yield keyword (i.e. generators and coroutines), which many other languages have had for a while.
* A sensible and simple built-in password hashing API
* Error when using the deprecated mysql extension, which should hopefully get more people moving to PDO (e.g. WordPress: http://core.trac.wordpress.org/ticket/21663 )
Here's hoping it gets merged in the next 5 major releases. I'm not holding my breath.