I have created a command line program that syncs Jira to Omnifocus. It will import all issues assigned to you in Jira to a project of your choosing in Omnifocus. Then, when you mark the task complete in Omnifocus, it will transition to resolved in Jira.
I am just curious if anyone else has any interest in this and if so, if there are any features you would like to see. It requires Node.js to be installed but given this, there are a lot of capabilities (full web server, email notifications, mac notifications etc) so let your imagination run wild and I will see what I can implement.