DNF 0.4.9 adds back support for several Yum features including dnf history rollback and also adding a history userinstalled sub-command for finding out packages the user manually installed. DNF 0.4.9 also has its API extended where it now finally supports the use of plug-ins. Up to now the API only provided a limited set of plug-in hooks.
DNF 0.4.9 also brings various bug-fixes and other minor improvements. More details on the DNF update can be found via this DNF blog post and the official release notes.