In order to list all the System Stored Procedures in SQL Server 2005/2008, you can query the sys.all_objects catalog view, that displays all schema-scoped user-defined objects as well as system objects.
SELECT NAME FROM SYS.ALL_OBJECTS WHERE type='P'
Similarly to find CLR Stored Procedures, use type=’PC’
SELECT NAME FROM SYS.ALL_OBJECTS WHERE type='PC'
Note: You can add ‘is_ms_shipped = 1’ to the query if you intend listing only those objects created by an internal SQL Server component.