An automated review which takes seconds? What will it be looking for exactly? Seems to be something that will either break every extension out there or will be so easy to bypass that it won't do much.
"This is not the same process that currently applies to AMO add-ons, which has been typically slower."
Also the fact that you can't seem to be able to disable it even with some "debug/developer" mode in FF seems to be a bit over the top.
What happens if you are tied to an older FF extension that isn't signed? What happens when you want to develop an extension? yes beta extensions will be signed also but what happens before the BETA what happens when i just want to make hello world and to learn what i can do?