I'd imagine closer to 4.7mil, broken down something like:
US-2mil
JP-1.5mil
EU-1.2mil
Just speculating, really. But it's a quarter of the way to the US target, and with a 3rd week WW around 500k+ (I'd imagine) it should be able to hold on to the Wii this first year. It's January onwards where the fight begins.