Did you guys ever implement this? I have a couple of other quirks both with SQL 2000 and SQL 2005 that are along these same lines...
1. I can't differentiate between stored procedures and user defined functions to provide only stored procedures in the list, in the GUI.
2. I have an add-in which parses out the ProcedureText of MSSQL stored procedures in order to populate User Meta Data with any default values found for the parameters. That add-in basically scans through all of the procedures in the database and I'd like to be able to skip any system stored procs, user defined functions, etc.