Out since August 1st (see URL).
2.3.1 out since September 1st (see URL).
+*mercurial-2.3.1 (11 Sep 2012) + + 11 Sep 2012; Lars Wendler <polynomial-c@gentoo.org> -mercurial-2.2.2.ebuild, + +mercurial-2.3.1.ebuild: + non-maintainer commit: Version bump. Removed old. Permission kindly granted + by djc.