Apologies if this has been asked already, but would it be possible to write an extension to give admin the option to give users the option to turn on/off optional extensions, eg maybe the namewhore tab etc?
I think that option would have to be written into the extension itself, and remembered via the DB in a table row somewhere. But it seems totally possible.
Mark says this about adding user preferences for specific extensions:
Everyone should note that if you are looking at creating an extension that turns on based on user preference, you should hold off on altering the database in any way. I'm going to be writing the documentation on user preferences and everyone is going to love what I've done (no database changes should be necessary for adding new user preferences).