Have Nintendo opened any new factories, or bought any? Not as I know.
Nintendo doesn't own any factories. So no.
But they are under contract to have twice as many units produced per month than they were last year at this time. While 250k/week was their average for last year and it was constrained by production, closer to 500k/week will be their production level this year.
Wii = 38 million.
360+ PS3 = 40 million.
These numbers are low on both sides. The PS3 may approach 20 million by the end of 2008, and the 360 should be around 25 million. The Wii should be above the 40 million mark (1.8 x 12 = 21.6). The issue is that the 360 and PS3 will make most of their sales near year end, whereas the Wii should do well year round so it could very well surpass 50% during 2008 and end just under 50%.