It's particularly interesting to OS X prefix user since it introduced a new plist library that can handle binary plist files. Also the official 3.4 binary from python.org doesn't include readline support. Reproducible: Always
This needs a new patchset, which is quite some work.
apparently gx86 went with the flow and made this the default python :/
I grabbed python-3.5.0-r1.ebuild from gx86 and it works just fine. python-3.5.0-r3.ebuild seems to fail during installation.
Python 3.5 has been there for a while.