Re: OK… How painful is the transition from MU to WP 3.0 going to be?
I laughed too, because is_super_admin is already being used in premium wpmu plugin which enabled one WPMU install to create sub-WPMU installs with own domains mapped (instead of usual sub-blogs). i did wonder when I saw the replacment name if decision for choosing is_super_admin was the “path of least resistance” and provided relief to those who used the plugin or maybe it really was just the Superman reference 
