At last my Nokia Lumia 800 gets its firmware upgrade to allow tethering. The 8773 update seems to be made up of three updates, two operating system ones (which I managed to force down in the usual way), but this Nokia firmware one has taken weeks to get to me, forcing did not help. I had to wait.
I don’t think I am alone in not being too impressed with the update process. The throttling/delaying update process is probably Ok for the man in the street, who just wants a working phone, but there should be an easier way to get updates if you want/need them ASAP for development purposes or are trying to run consistent versions for all phones in an organisation.