Could a warning be displayed when issues or screens are being updated on other machines or browser tabs? For instance if you are updating a workflow, perhaps there could be a warning that the workflow page is being accessed by another user or if the page is open on other browser tabs. There is a plugin that has been created to alert users when multiple users are accessing/updating the same issue. See the following link:

http://confluence.atlassian.com/display/JIRAEXT/JIRA+Visitor+Plugin

Initially it would be nice to limit the function to admin users and only pages they have access to such as workflow pages, permission pages, and other system critical pages. Could something similar be added to JIRA?