The comment from Garrett prompted this entry, as I'd like to clarify I'm not standing up against Artistic2 at all. :-)
I don't consider Artistic2b14 as restrictive at all (except maybe the TPF-can-update-terms-at-will clause feels a bit strange); it's certainly an improvement over the extremely ambiguous Artistic1. If you agree with the intent of Artistic1 for your previously-released original work, and trusts TPF's continuous licensing direction, then upgrading to Artistic2 is definitely a sane choice.
Re Garrett's Parrot/Artistic2 concerns, Allison noted that the "Copyright by Perl Foundation" header added to each Parrot file does not override the original author's copyright, but instead means that TPF holds the compilation copyright, by which it must be asserted to extend to all files within the Parrot tree, which means Parrot can't contain LGPL parts, or any parts that are more restrictive than Artistic2.
So to solve this problem, I simply disclaim my compilation copyright over Pugs, as well as the tarball that contains third-party (BSD, Artistic/GPL, and possibly LGPL) distributions. This means the receiver must reuse part of the code under whatever license it was originally under.
In addition to disclaiming my right to the compiled work, I also disclaim my original work contained within it, so that the receiver does not need to worry about reusing those parts of the work. Once all the non-third-party parts are marked as such, then we can say that "the entirety of Pugs is in the public domain". Until that day, it means that the Pugs tarball doesn't impose any licenses at all, beyond the licenses in whatever its subdirectories assert. :-)