I lost track of the ~~'s return value in list context issue, which you brought up to p5p: how did it end?

The answer in short was "we don't know if it's a bug or a feature because we don't know what ~~ should really do". (Not literally, though).

The fine p5p hackers long wanted to review smartmatch semantics, and this question encouraged them to actually do it. aristotle is now investigating how the Perl 6 smartmatch semantics changed since the perl 5 version was implemented, and plans to give p5p some feedback. Then they (or we) will try to decide what the best semantics for Perl 5 are.