On the php[architect] site they've shared another article from their September 2018 issue. In this new article author Damien Seguy looks forward to PHP 7.3 and covers some of the new features that come with it.

PHP 7.3 successfully passed the “feature freeze” deadline. On Aug. 1st, 2018 all features for PHP 7.3 were identified. This triggered the first PHP 7.3 beta, on the following day, and, from there, we’ll reach RC in September. It is time to review what this new PHP version has available for us, help test PHP 7.3, and get ready.

He goes through several of the changes coming including:

• Improved Garbage Collector
• Relaxed Heredoc/Nowdoc
• Trailing Comma for Calls
• Deprecated Case-insensitive Constants
• PCRE 2.0
• SQLite 3.24
• Json_encode May Throw Exceptions
• array_first_key(), array_last_key()
• list() with References
• is_countable()
• net_get_interfaces()
• Removing image2wbmp()
• assert() is Now a Reserved Function
• Continue for Loops, Break for Switch
• Monotonic Timer: hrtime()
• compact() Reports Undefined Variables

For each of the items listed, there's a brief explanation of what the feature is and some code to show it in action. The tutorial ends with a listing of some things you can do to prepare your current codebase to work with PHP 7.3 ahead of the December 13th release date.