I understand Wii is projected to about 10 million units by September. Figure another 6-10 depending on supply for the holiday. So I'm guessing between March and June.
The 360 obviously has no trouble with supply. I figure on a price drop come Fall. The sold about 6 million this holiday. With a price cut, Halo 3 and GTA4, have to expect to better that number this year. So I expect about 8-10 million sold this holiday, and passing its predecessor by June. Of course most of these sales can be attributed to the same 43 people who have to get new 360s every other week.
And even though you didn't ask, I figure the PS3 will surpass the PS2 sometime in 2023.







