Note that the 'Synopsis' has been demoted to be closer to a set of design docs than a formal specification - it's more about the test suite these days (cf first two paragraphs of http://design.perl6.org/).

Jnthn made a list of things that are supposed to be fixed by Christmas [1] as well as a list of things that probably won't make it into the 6.0 release [2].

[1] https://rt.perl.org/Public/Bug/Display.html?id=123766

[2] https://gist.github.com/jnthn/040f4502899d39b2cbb4