The 7th generation isn't over just yet, while initially the Wii dominated, with the Xbox 360 coming in second, and the PS3 a close 3rd, things started changing. For starters the Wii sales stalled, then had a sharp decline and has been selling poorly for the past year or two, the PS3 has now over taken the xbox 360 putting the PS3 in second and the xbox 360 in a close third, Both the PS3 and Xbox 360 are still selling fairly well despite the successor console from both coming out at the end of the year.
If the PS3 and xbox 360 get a price cut for the holidays, or shortly after they will continue to sell fairly well into the life of the newer consoles. PS4/X1 for the early adopters, and PS3/360 with the price cut for the casuals who can't afford the newer machines or simply can't justify spending that money on the newer consoles but are fine with the older cuz of the huge game library and that fact that both Sony/Microsoft and 3rd party will still support the PS3/360 going forward for a few years.
So it's not a black and white situation, there is potential for either the PS3 or 360 or in fact both to surpass the Wiis life times sales before Sony/Microsoft stop manufacturing them. Just take a look at Sony, they've delivered on that 10 year life span for its consoles, with the PS1 and then PS2, with the PS2 having like 12-13 years life.
When all is said and done, I do foresee the PS3/360 matching or exceeding the final install base of the Wii. As of now the PS3 is behind the Wii by 21.6 Million. For the year of 2012 the PS3 sold 12,734,949 (according to VG number), so if Sony keeps selling the PS3 for the next 3 year and manages sell another 30 million then they should comfortably overtake the Wii life time sales...
Yes I am aware that the Wii will continue to sell but it's been trickling in sales, in the past 6months (Jan-June) the Wii has been selling an average of 176,664 per month, while the PS3 has been selling an average of 709,420 per month (numbers from VGchartz), the Wii sales will continue to decline further as the year goes by allowing the PS3/360 to catch up in a matter of years, I'm predicting 3-4 years.
I guess time will tell, but till then this is what I predict, and remember, this generation isn't over untill the Wii/PS3/Xbox360 stop being manufactured. It's a marathon, not a sprint ~_^
