I'm a little confused about what this plugin will do. The warning on the page says:
Warning! This is a very dangerous plugin to activate if you have untrusted users on your site. Any user could add Javascript code to steal the login cookies of any visitor who runs a blog on the same site.
but above that is says:
Unfiltered MU gives Administrators and Editors the unfiltered_html capability.
So if should the warning read "Any user that's an Admin or Editor..." or can any user really run unfiltered code?