I use a slightly different approach (despite of the usp_)
I can divide my stored procedures to operate in different parts of the DB (CRM, Statistics, Reporting etc.). That's a module (call it whatever you want)
Then, I have objects. This includes all tables and views I'm operating on, but can also be something abstract like sales, inventory or so.
Finally, I would have actions operation on the objects. I would use 'Edit','Delete','Insert','Generate','Calculate' or whatever.
Now, if I sort the SP in the Enterprise mangager, I have them nicely grouped by module, object and action. procedures which operate on the same object in the context of a module are listed together. That's exactly what I need.