If we believe in history repeating itself let's look at history.. No console maker has EVER had more than one - two victories in a row I'll illustrate
Geneisis - Sega CD
NES - SNES - N64
Atari 2600 - atari 5200
Gameboy - Virtual boy
If we truely believe in history as the be all to end all sony couldn't win this generation thankfully history can be bunked Wii may very well latch it's victory and ride it for a while, at best PS3 would look to surpass it late 2009, and that's providing the Wii suddenly started selling 50% what it is now and PS3 doubled.. The PS2 had several advantages that the PS3 simply cannot afford and Blu ray won't help it's value like DVD did the PS2 because average consumers don't even know the difference and when they do see no point to the medium. With DVD vs VHS there was a clear benefit to everybody with blu-ray vs dvd there's not a clear difference to average Joe Six-pack.
i think history will be bunked and nintendo will make its thrsd victory,unless ofcourse wii stops selling(which will likely not happen)