Recommendations for PHP 6 'certified' code

Hi, I saw one post earlier at php-general asking for a list of recommendations / practices that should be followed to guarantee that code will run fine when PHP 6 comes out. I've searched and could not find a 'definitive' list of features that will change or be deprecated with PHP 6. Having such a list would be great since we could start to alert people so they can 'correct' existing code or start developing in a recommended manner to reduce further headaches...