As PHP 7 was released, should I apply for PHP 5 certification or better wait, until PHP 7 Certification will be released/announced? What plans does Zend have regarding this certification?
It all depends on why you want to be certified. If you want to learn only the new features it can be worthwhile to be wait for PHP7 certification. But if you need it for finding a job or convincing your boss that you understand PHP, you can better now get PHP5 certified.
I think it will take a few years before customers will adopt PHP7 and we will see a few years where 5 & 7 will be supported next to each other. A lot of legacy code will break because of dropped support for some modules. The mysql module is still used a lot.. for example.