The latest version in the tree is 3.0.0-beta3-r1, but 3.0.0 was finally released two weeks ago. https://github.com/google/protobuf/releases
It would be nice to have both 3.0.2 and 3.1.0 in portage.
commit dde8d15e2fc1a9c94a797dfa622e9e8a9b9e8529 (HEAD) Author: Aric Belsito <lluixhi@gmail.com> AuthorDate: Tue Dec 6 15:11:57 2016 -0800 Commit: Patrice Clement <monsieurp@gentoo.org> CommitDate: Thu Dec 8 21:35:54 2016 +0100 dev-libs/protobuf: version bump to 3.0.2 and 3.1.0. Gentoo-Bug: https://bugs.gentoo.org/591072 Closes: https://github.com/gentoo/gentoo/pull/3043 dev-libs/protobuf/Manifest | 2 + dev-libs/protobuf/protobuf-3.0.2.ebuild | 112 ++++++++++++++++++++++++++++++++ dev-libs/protobuf/protobuf-3.1.0.ebuild | 111 +++++++++++++++++++++++++++++++ 3 files changed, 225 insertions(+) create mode 100644 dev-libs/protobuf/protobuf-3.0.2.ebuild create mode 100644 dev-libs/protobuf/protobuf-3.1.0.ebuild PR merged, thanks!