Bulk of the effort is in developing MoarVM, which is likely to become a suitable replacement for Parrot. Documentation, Speed and standard libraries remain as open issues. Of which last I heard was Larry Wall was writing a Camel book equivalent for Perl 6. So its mainly speed and standard libraries.
I would give end of next year, by the time its ready for prime time.
I wish this claim wouldn't come up in every Perl article because that's a big part of Perl's perception problem. P6 is entering its 15th year of advocates claiming that it'll be ready in "about a year and a half".
If that claim is true this time, then it puts off people doing interesting things with Perl now as they figure they'll wait for a successor to look at it.
If that claim isn't true, then it puts off people doing interesting things with Perl now as the claim will change to be "about a year and a half from now" in another 18 months.
I'm of the opinion the only way to solve the chicken and egg usage problem is to convince a few people to be chickens. That's not going to happen without them trying it out. (I'm aware you've thought quite a bit on this issue).
Perl has a grammar? In seriousness, the old aphorism that "the only thing that can parse Perl is Perl" didn't help Perl. The tooling lags behind that available for other dynamic languages.
Up until last year, I did a lot of web development in Perl. Its strengths were CPAN & community, ubiquity and top-notch text processing. Its acquired taste was very elegant expressiveness once you grokked the grammar.
Then all the Perl leadership focussed on the black hole of Perl 6 which was solving a problem no one had but CS linguists. So Perl users like me felt there was no future in Perl. Perl 6 would have to be relearned for no tangible benefit so why not learn something new with a growing rather than stagnant/declining ecosystem? No one was forced to leave, but like a trap door, as soon as a Perl programmer learned something new, they were only going to continue to decrease their use of Perl.
The rise of Python and Ruby (and Ruby on Rails especially) and even PHP, were grave wounds to the health of Perl, but Perl 6 was the self-cutting that bled the community beyond the point of self-repair.