Backport of 1.6.1 to precise?

You are talking about git not git-flow? If so, please adapt the package ("For:") setting above! Thanks!

And BTW: Recent git versions can be found at: https://launchpad.net/~git-core/+archive/ppa

Erm.
Nope.
git-flow I'm asking for.

I do installations of current git-flow versions on my precise system via installation scripts from
https://github.com/petervanderdoes/gitflow

...but it's not managed (by apt) and installs in /usr/local/...

The version number of git-flow in Ubuntu jumped from 0.4.1-2 for saucy to 1.6.1-0ubuntu1 for Trusty (in development)!

I do not see any dependency problems, so you might try to manually install the http://launchpadlibrarian.net/154775764/git-flow_1.6.1-0ubuntu1_all.deb file
Caution: installing packages that have been created for a different Ubuntu release can work well, but might also fail miserably due to broken dependencies.

If a manual install works well, a backport of that package to precise-backports should be no problem.

Manfred, you are right.
Flawless installation:

~$ dpkg-query --show git-flow
git-flow 1.6.1-0ubuntu1

~$ git flow version
1.6.1 (AVH Edition)

~$ git --version
git version 1.7.9.5

For making the 1.6.1 version available in the official repositories, you now might request a backport, see https://wiki.ubuntu.com/UbuntuBackports
You have to be aware, that for a backport to precise also backports to all later releases (quantal, raring and saucy) need to be done, to allow for a flawless upgrade from precise to higher releases.