The important thing to note from this release is that Joomla 3.3 will REQUIRE PHP vesion 5.3.10 or later. This is because PHP 5.3.10 contained a critical security fix:
Now is a great time to make sure your web server is running a compatible version of PHP, with 5.4 or 5.5 being a better option for performance reasons. Joomla version 3.2 will be maintained with security updates through October 2014, so you do have an option if your host does not have a newer version of PHP for some reason.