The next major release of PHP, version 7, is going to be an awesome release. Not only will performance be greatly improved, there probably will be lots of nice changes to the language.
The procedure on how PHP gets changed is easily readable and well documented. In short it comes down to this:
- Proposed changes are submitted on the PHP Wiki.
- There is a RFC (Request for comments) phase in which key members of the community and contributors can discuss the change.
- After this round of discussion, which lasts a minimum of two weeks, they can vote if the proposed change gets implemented in a next version of the language.
If you want to closely monitor the future of PHP here's a tool to monitor all activity on the current RFC's.