I have not followed the license elaboration/approval process and I didn't even know what changed. But the license is incredibly clear and (I think) the essence is that paragraph by Allison:
Since the Artistic 2.0 allows relicensing under any pure copyleft license (which includes the various versions of GPL and LGPL), the effect of the dual licensing model is now handled by the Artistic 2.0 alone.
That means there's no issue anymore about the dual licensing of the code which adopts this license. You adopt Artistic 2.0 and that's fine. Will Perl 5 adopt this as well?
For CPAN authors, many release under "This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself" and stick "license: perl" into the META.yml/Makefile.PL/Build.PL distribution files. I suppose that, when times comes, the search.cpan.org will show that as "License: Perl (Artistic2)" instead of the current "License: Perl (Artistic and GPL)". Right?
Update: Uhm, I haven't seen Artistic 2.0 approved by OSI before I wrote that entry. It's because I hardly look to everything else but the "Recent Journals" section.