Picard 0.13 was recently released and thanks to the packaging efforts of Michael Wiencek we now have a working Mac DMG for Intel Macs running OS X 10.4+! At this point we do not have any support for older PPC Macs and it doesn’t look like we will ever have support for that. Sorry. There is an older 0.11 Universal Binary that PPC users can use.
Download your Picard version 0.13 binary version now!
Thanks to Lukáš, Philip, Michael and everyone else who worked on this release!
UPDATE: You see a change log for this release here.
MetaBrainz Blog 
Cool. But the changelog linked on http://musicbrainz.org/doc/MusicBrainz_Picard ends at v0.12.1.
What new stuff does v0.13 have ?
(and btw, I think these working and stable recent versions of Picard deserve the 1.x mark)
http://forums.musicbrainz.org/viewtopic.php?id=2614
Changes are listed on that forum post. However the change about rounding seems a bit premature. I have a few files which get rounded and shouldn’t. like a 1:11:497 (one minute, eleven seconds and four hundred ninety sevenths of a second) file, it gets rounded to 1:12 instead of down to 1:11
Sweet, now it closes clean on Win7 64. Used to always close with an error asking to look online for solution.
I don’t see a “binary release” for Linux anywhere as advertised in the headline. At least there are already some Ubuntu packages available here:
https://launchpad.net/~phw/+archive/musicbrainz/+packages
FWIW, I’ve fixed the changelog link on http://musicbrainz.org/doc/MusicBrainz_Picard