Jeez everyone is pessimistic for console sales.
20m for the 360? It's already sold half of that!
As for the Wii -
The lifespan really depends on how demand goes when the Wii starts going against a mass-market price against the 360 and even PS3. The Wii has the advantage of being blindingly cheap compared to either system. Once the 360 hits that price, Wii sales *could* drop, and once the PS3 does it, so could they.
The Wii is trying to get new gamers, not cater to the older ones. If thats truely the case, we have about 150m gamers that bought Xboxes or PS2s that *might* not buy a Wii...Thats a huge #.
The big question is (to answer the Wii longevity question): How many PS2/Xbox owners will buy Wiis? If there isnt a large #, then the casuals will drive Wii sales, allowing for the major/mid major titles to goto the 360/PS3, lowering dev support for the Wii at some point in the future, and eventually hurting it in 2008-2009.
IMO, I see a new Wii (an actual new Wii w/ a CPU/GPU upgrade and other real revisions, not a Wii lite or WiiHD) in 2010.
Back from the dead, I'm afraid.
