I could see other benefits for this.
I own & admin a few different forums, and I quite often don't want to particiapte as the owner, but just moderate. Why? I don't want my users to think that I have an unfair advantage, so the normal user can participate, and they don't know it.
The only workaround I have now is to use Firefox for the one account, and IE for the other. Even running Opera @ the same time, not logged in (acting as a Guest), I could easitly test different permissions on the threads