Ayesh Karunaratne made a good summary of the new stuff coming in PHP 7.3 which will be released by the end of the year.

This is a live document (until PHP 7.3 is released as generally available) on changes and new features to expect in PHP 7.3, with code examples, relevant RFCs, and the rationale behind them, in their chronological order.

https://ayesh.me/Upgrade-PHP-7.3

The trailing comma in function and method calls seems nice!