Inertia and momentum - at least currently, Pugs-on-Haskell has all the momentum, and Perl 6 development has shown a lot of inertia. Of course, maybe some time somebody starts a topaz-like effort to implement Perl6 in itself; and this time, it's much more likely to succeed, as Perl6 has enough power to become self-sustaining (unlike Perl5), and can maybe even have a straight first machine-generated translation from Haskell. But I don't see that this will inevitably succeed, while I see the success of Pugs/Haskell immediately.

Perl 6 development has shown a lot of inertia

Since "inertia" means both "things at rest tend to stay at rest", and "things going quickly tend to remain going quickly", what exactly did you mean by this statement?

Are you saying "Perl6 development is unstoppable!"?

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

I mean both. For the last five years, Perl6 development itself was mostly stagnant. Now, it gained lots of momentum, but not through the people originally involved with it. I think it will keep going in that direction, at least until the personae dramatis change again.