There was a bash-completion support in maven2 package prior to 2.2.1 update where it was removed by mistake. See commit http://pkgs.fedoraproject.org/gitweb/?p=maven2.git;a=commit;h=844122dc0ef40956d7e037e273eee10f23bc1f5a It would be good if this is resurrected in the maven package and enhanced with zsh support as git guys are doing, see https://github.com/git/git/blob/master/contrib/completion/git-completion.bash for example.
Done in rawhide: http://koji.fedoraproject.org/koji/taskinfo?taskID=3231334