I just tagged Edit Author Slug a few minutes ago in the WordPress plugin repository. It has gone live on WordPress Plugins Directory, and will likely be available via auto-upgrade within the next 24 hours. No major changes in this release, as this release was mostly about usability enhancements.
Edit Author Slug now adds an “Author Slug” column to the user list in the Dashboard (Users > Authors & Users for 2.9.x and Users > Users for 3.0+). Thanks to Yonat Sharon for the code jumpstart. I altered the processing of the author slug before saving, which has allowed for a wider variety of characters. You are no longer restricted to alpha-numeric characters and numbers. Aside from that there were a few minor bug fixes. Most of the bug fixes were just things I wanted to do better. Hope you continue to find the plugin useful!