I think its wishful thinking that the wii will be at 120 mil in 3 years to tell you the truth.
3 years for me
Wii 85 mil
PS3 55 mil
360 40 mil
And yes, I do believe Wii's sales will decline, so don't ask why i project low Wii numbers ok. Give or take 5 mil to my numbers depending on what happens.