Just some basic number crunching and excel fun...
The 3 month to 12 month American sales ratio of all consoles (listed on Gamerankings):
( 3 month / 12 month ) = ratio
Dreamcast: 1,138,500/2,110,500 = 0.708
Nintendo DS: 1,607,000/2,754,000 = 0.583
Gameboy Advance:1,876,000/7,682,500=0.244
Gamecube:1,362,250/2,634,500=0.517
N64:1,294,250/3,884,000=0.333
Playstation:340,500/1,421,500= 0.239
PS2:1,309,750/4,643,500= 0.282
PSP:1,341,750/4,396,250= 0.305
Xbox:1,789,000/3,526,750= 0.507
Xbox 360: 929,750/3,195,500= 0.290
Min: 0.239
Max: 0.708
Average: 0.401
*Realistic: 0.372
Using these ratios we get sales for the Wii at:
Max: 7,214,999
Min: 2,439,435
Average: 4,308,240
*Realistic: 4,637,951
And sales for the PS3 at:
Max: 4,322,946
Min: 1,461,614
Average: 2,581,329
*Realistic: 2,778,879
Which would mean for the rest of the year the Wii would need to average (approximately)
Max: 600,000 per month
Min: 80,000 per month
Average: 290,000 per month
*Realistic: 325,000 per month
And for the PS3:
Max: 365,000 per month
Min: 48,000 per month
Average: 172,000 per month
*Realistic: 195,000 per month
*Realistic removes the two highest and the two lowest ratios ...
The only reason I made this post was so that people could understand how unprecidented it would be to see the PS3/Wii sell at some of the levels people suggest ...