Jan Šilhan finished and got merged his initial patch to support Python 3 in DNF last week so we released a new version yesterday. The 0.4.4 also includes a couple of tweaks to the slowly emerging API and a fix to the bug where DNF ignores the file conflicts and naturally finishes the transaction set.
About Python 3: do not expect
dnf install package and similar to run from CLI just yet, we are still waiting for F20 GA for all the components involved to be available for Py3. Many thanks to Tim Lauridsen for quickly porting python-iniparse. The plan now is to give Py3 and DNF heavy testing during the Fedora 21 development cycle and eventually switch to it as the default. Then drop Python 2 support as soon as Anaconda is running in Python 3.
Read the full release notes to dnf-0.4.4.