Of course it isn't Christmas! Black Friday to December 24 in the USA is like 40% of sales for the market for the entire year.
The week leading into Golden Week (people travel, rest, relax during the actual week) is like a good week of sales plus a 10-30% boost over normal. Then Golden Week and the week after are a bit higher than normal as well, before a large dropoff into normal or summer sales patterns depending on the strength of software available.
As for the Ninja Gaiden Xbox numbers..PS3's userbase is already much larger..I think the bump percentage in overall hardware sales will be similar. If Xbox got like a 20% jump (if it went from say..3500 to 4200 per week), then I would imagine PS3 will jump 20% (from say..11,000 to 13,200) for a week or two when it comes out. Still if it was only a 20% boost, then I'm going to adjust my max weekly PS3 numbers down. I'll throw in 360 numbers as well since Trusty Bell comes out in June.
I just see sales like this for the next 10 weeks (from highest to lowest, not by date):
Wii : 88k, 83k, 80k, 77k, 74k, 70k, 66k, 65k, 65k, 65k ~ 73,000 per week for 10 weeks
PS3: 18k, 14k, 13k, 11k, 11k, 11k, 10k, 9k, 9k, 8k ~ 11,000 per week for 10 weeks
360: 12k, 8k, 5k, 5k, 4k, 4k, 3k, 3k, 3k, 3k ~ 3,800 per week for 10 weeks
Basically, right around when Dragon Quest Swords (7/12/07) comes out, Wii should have a userbase around 3 million, while PS3 will likely be in the low 1 million range when Heavenly Sword or other big games come out...