In this new post to the PHP 10.0 blog Stas mentions some of the other syntax options he's like to see in PHP including:

• a()() - When a() returns a callable object (such as a closure) the second set of brackets would call it.
• foo(1,2,,4) - Syntax to skip a parameter in a call, which then will be substituted with the default as defined by the function.
• $a = ["a", "b" => "c"]; - I’d really like to have short array syntax. Yes, I know it was rejected so many times already, but I still like it.

Be sure to catch some of the good amount of comments with options from others about Stas' suggestions.