there's a number of threads here on SSC where the requirement is to remove public permissions in order to comply and lock down a SQL server to DoD standards (google Database Security Checklist for examples).
In that ,we just don't care what breaks.
see this thread for an example:
http://www.sqlservercentral.com/Forums/Topic845604-392-1.aspx#bm845742
and take a look at this link for a more comprehensive script.
http://blogs.technet.com/b/fort_sql/archive/2010/02/04/remove-public-and-guest-permissions.aspx
Lowell