From IGN.com here is the Japaneese game release schedule for the PS3 ... This is probably not accurate much past June because more games will be announced at E3 (June) and TGS (September).
From the looks of it, over the next 10 weeks there is really very few games released and we could see the PS3 weekly sales numbers drop below 10,000 (or even 5,000) units per week. I'm leaving the Wii release list off (mainly to prevent scrolling) but the releases for the Wii are far steadier and interest in the Wii should remain high; I suspect the Wii will sell nearly as many systems as they can produce.
I would say the Wii will pass 3 Million before the PS3 passes 1 Million by a couple of weeks.