Lukas Smith asks developers a question in his latest blog post: "Is your chosen framework on the PHP primary tester mailing list?"
This is a question you should be asking the developers of the framework you are using. Same of course goes for any PHP application you care about. [...] We announce all PHP releases on this list (actually until now we have only announced RC's, but we are expanding this to also cover alpha and beta releases).
He suggests that subscribing to this list simplifies the process of keeping up with the latest releases of PHP and gives them a chance to report back with any issues they might find with them.
Every release runs the risk of BC breaks, intentional or not. Projects that want to make life easy for their users participate actively in the process of testing PHP releases. It makes the life of the PHP developers a lot easier .. and who doesn't want to make their life's easier?