Shams, like you said, that was skewed by the release of two new consoles, and even then the week after thanksgiving was a decent increase.
And it's difficult to apply such a scaling factor to a console destined to be supply constrained, the numbers you finished with might be more representative of the Wii demand.
And yes the final week that extends after christmas does include christmas eve, (and due to the irritatingly skewed week endings, the 23rd for America too) but that is only one day, which is why i don't think that will be the biggest week of the year but more on par with the week ending 15th/16th.
The 24th may be THE biggest day, but the week ending 23rd has 7 of the next greatest days.