For some reason the instructions specify that you'll have to have wifi and battery charger connected. I had 3G and no charger, battery was around 60% when started the update. Update went smoothly and battery was 36% afterwards. (Display was all the time lighted up, slow 3G connection).

Some of the new hints do annoy me, just like somebody said earlier in this thread.

They might help new phone users, so I hope they will disappear after a while. I mean after I have seen all the hints couple of times.