Well perl6 development is organized differently. I personally wouldn't call it a "community's rewrite".

p5p is also a community as parrot-dev is, but parrot/perl6 hackers more are sponsored than p5p,
and the process is more "business orientated", than in p5p.
At least it's faster and more practical in perl6 land.

git e.g. is decentral and more community oriented than svn.
Monthly parrot/perl6 releases is more practical than the chaotic p5p release process. chromatic recently summarized the differences on p5p.

But we have completely different projects here.
perl5 dev. is mostly bugfixing and discussion,
perl6 is only about adding the missing features.
perl6 has a tight and organized roadmap, with stable and bound ressources,
the perl5 roadmap is "flowing", as the ressources come and go.