The main feature of DNF 0.6.0 is support for advisory listings via the updateinfo sub-command to DNF. This drop-in replacement to Yum also now supports the include configuration directive and there's improvements to group operations. A handful of bugs were also fixed by this latest release.
More details on DNF 0.6 can be found via this blog post and the release notes.
DNF has been an experimental package management option going back to the Fedora 18 days and since earlier this year has been called ready for user testing though not everyone is happy about DNF. DNF isn't expected to replace Yum by default until Fedora 22, which now will come sometime in 2015.