Saying this generation has peaked is untrue. Then again it depends on how you look at it.
The way I look at it is through the overall sales of the consoles. Therefore I say it has not peaked.
This generation is unique in that sales are spread far more evenly between the three competitors, consoles are taking sales of each other.
Therefore combined sales of wii, x360 and PS3 are almost 190m and growing.
Last gen PS2 was way, way ahead and xbox and gamecube was no where to be seen. I am not sure of the overall sales (as PS2 is still relatively strong in developing countries) and by the time they "died" the approximate sales where less than 190m. (PS2 125m, GC 21m, xbox 24m)
Doing a YoY every week is misleading. What is required is a YoY done yearly.
Below are extremely rough figures and I see some yearly growth and expect it to continue.
Xbox 360 (worldwide)
2006: 10m
2007: 19m
2008: 30.5m
2009: 38m
2010: 49m
edit: Reworking the PS3 figures. I have screwed this up. What I wanted to do was produce was a chart showing the overall rise in combine sales of all home console during the last 4yrs...help. IE keeps crashing and copy and paste has gone mad.
