Yeah, we'll see. Personally, I don't think 400k is very impressive in the month you launch (and the biggest shopping month of the year), especially if you weren't particularly supply constrained. I'd be surprised if the December numbers were very good. The word of mouth around the Wii U isn't very good.
What other launches did more than 400k first week? The Wii u didnt do 400k in a month!!