What is the lowest realistic expectation for lifetime sales of Wii,PS3,360?

[spartan117]

Xbox360

min: 35 Mio
estimation: 60 Mio
max: 110 Mio

Wii

min: 45 Mio
estimation: 80 Mio
max: 140 Mio

PS3

min: 25 Mio
estimation: 45 Mio
max: 120 Mio

as you can see, the PS3 is very difficult to estimate...