Edited: the question about update size has been solved, at least for me. I finally got the update applied, after six hours and one break in the download. The Wii U managed the break ok: it just gave an error code and said the internet connection could not be made. Afterward it resumed from where it left off.
I monitored the network bandwidth from my router, and during the six hours it recorder 926 MB downloaded, so not that much after all. The actual download could have been 920MB but that's nitpicking.
There seems to be something slowing down the wif, and that might be caused by the Wii U. On the other hand, the servers could also be overloaded, although Nintendo seems to be using Akamai technologies, which usually provides the best (and fast) service.
This is from Finland, so perhaps my update was smaller than someone else's, or maybe its the same everywhere irregardless of launch date. Our launch date was the same as in UK and Europe.
Edited by Greenleaf, 04 December 2012 - 07:34 AM.