The Texinfo licensing is compatible with Perl.
Actually, it's not. As far as I could determine in a few searches, it's released only under the GPL, which means it cannot be included in the core Perl distro. Everything in the Perl core has to be released under the dual-license (GPL + Artistic).
If Perl6 were to use an existing doc standard from which to base it's Pod, it would make sense to me that an implementation of this existing standard would simply be listed as a prerequisite, rather than actually being distributed along with Perl6 proper. That's part of the price for choosing to use an outside implementation of an existing doc standard for one's software project. Maybe that's not acceptable here though. I don't know what the Perl project policy is on that.
Which means, we'd need to rewrite the entire Texinfo application. Are you volunteering?
Not as such, but thank you for the offer. :) BTW, I don't mean to be making any requests here. I hope my posts don't come off sounding that way. Incidentally, if the Perl6 team specifically wanted to use an existing (non-POD) standard specification and then write their own implementation, I bet we'd be able to scratch up some usable pod62man and pod62html scripts very quickly.
From what I can tell, a main reason for not reinventing the wheel here is to allow many users to write their docs using markup and tools with which they are already familiar. Their existing tools may have features they can't live without (like having TeX draw their mathematics, or easily being able to include screenshots in their docs).
Now, if Perl6's Pod is general enough that folks can use it for documenting things that have nothing whatsoever to do with Perl, and if it's nifty enough that they'll actually *want* to document those things in Pod instead of their current favorite, then maybe it's worth taking the time to reinvent Perl5's POD. I think it would be great if it turns out to be both.