Honestly? Time. Time is the best source of how well or poorly a console does. Right now, it looks as though the Wii has this generation in its pocket and the PS3 is going to spend the whole time trying to catch up to the Xbox 360.
But... this has happened before (to a significantly lesser degree, though). It is entirely possible that this can turn a 180 in the blink of an eye. Faster than you can say "What happened here?"
It's been less than a year into the lifespan of the Wii and PS3, and less than two into Xbox 360's. I would wager than by the summer of 2009, the generation will be set in stone. Currently, the PS3 is failing. The Xbox 360 is unhealthy, but surviving. The Wii is flourishing. But it can all change.
PS3: 5.51m/51w, avg 108,039/w (up 239)
360: 12.93m/102w, avg 126,764/w (up 625), leads PS3 by 7.42m (up 70k), avg lead 18,725/w (up 386)
Wii: 13.52m/51w, avg 265,098/w (dn 1,102), leads PS3 by 8.01m (up 90k), avg lead 157,059/w (dn 1,341)
If 360 sales stabilize, PS3 sales increases needed to pass 360 by...
01/08: (008w) +875.8%, 04/08: (021w) +344.4%, 07/08: (034w) +219.3%, 10/08: (047w) +163.5%
01/09: (060w) +131.8%, 04/09: (073w) +111.4%, 07/09: (085w) +098.1%, 10/09: (099w) +086.7%
If Wii sales stabilize, PS3 sales increases needed to pass Wii by...
01/08: (008w) +1072.%, 04/08: (021w) +498.4%, 07/08: (034w) +363.4%, 10/08: (047w) +303.1%
01/09: (060w) +269.0%, 04/09: (073w) +246.9%, 07/09: (085w) +232.6%, 10/09: (099w) +220.3%
If PS2 sales freeze, Wii sales increases needed to pass PS2 (as of Mar07, 108.4m) by...
2008: (008w) +4373.8%, 2009: (060w) +0496.5%, 2010: (112w) +0219.6%, 2011: (165w) +0116.9%
2012: (217w) +0064.9%, 2013: (269w) +0033.1%, 2014: (321w) +0011.5%, 2015: (376w) -0004.8%
At +0% it will pass it in 358w, the week ending September 19th, 2014, at an age of 409w (7y44w).
Current age of PS2: 7y37w.
Last update: Week ending November 3, 2007
