Ok heres a list of reasons why I believe the Wii will die the death is surely deserves, debate would be appreciated.
1. It is based on a nancy Gamecube ATi graphics processor while the 360 and PS3 are based on innovative NVIDIA processors.
2. It's medium; DVD pales in comparison to HD-DVD and Blu Ray and when games start to become to large to fit on DVD's developers will begin to turn away from the Wii.
3. It's controller uses batteries which are ultimately expensive.
4. It is unable to play DVD's, HD-DVD's or Blu Ray OR play generic video files. Oh but it can display static photos, hardcore.
5. Most of the games on the Wii are shallow First Party or Third Party titles which are essentially just re-hashed versions of past games (Twilight Princess, Metroid Prime 3 etc.). Also some Third Party developers have begun to release generic puzzle or simple 3D side scrollers which is an example of how developers don't actually take the console seriously.
6. In the end if the Wii didn't have the Wii-mote it would simply be a rather ordinary, graphically unimpressive console that focuses mainly on party games with little one player incentives to survive. It's gimmick incarnate and when developers begin to say "Hey! our games look like shit on this thing!!" support will dry up and you will all be left out in the cold.
Now let's have some rebuttle.