I've done some work porting the bzr-jira plugin to jira4.
The main branch is available on launchpad at https://launchpad.net/bzr-jira
My branch is available at https://code.launchpad.net/~mattiasa-avm/bzr-jira/jira4
A binary release can be found in downloads
$Id: index.html,v 1.4 2010/10/03 08:51:32 mattiasa Exp $