Are you telling me that if Wii sold no consoles for the entire year of 2010, it would still be ahead of PS2's sold for its respective year.  That can't be right, can it?

I eyeballed it, earlier, but I just checked.

If the Wii stopped selling as of the last charts (so the 13th), and 52 weeks passed the Wii would only be behind by ~60k

http://vgchartz.com/hwlaunch.php?cons1=Wii&reg1=All&cons2=PS2&reg2=All&cons3=PS2&reg3=------&weeks=221
If you go by global sales from first launch that is indeed correct. The Wii just had it's 169th week, and it's at 67,510,630. We'd have to go all the way to the PS2's 221st week to pass that amount with 67,565,085. That's a full year later, which is obviously a few weeks past the end of 2010.

This could be considered "unfair" though due the staggered launch of the PS2; however, as Rol points out PS2 had shortages anyway, and even if that weren't the case I doubt the amount of sales over a 3+ year period would've increased drastically if it were available earlier.

http://vgchartz.com/hwlaunch.php?cons1=Wii&reg1=Japan&cons2=PS2&reg2=Japan&cons3=PS2&reg3=------&weeks=221
http://vgchartz.com/hwlaunch.php?cons1=Wii&reg1=America&cons2=PS2&reg2=America&cons3=PS2&reg3=------&weeks=221
http://vgchartz.com/hwlaunch.php?cons1=Wii&reg1=Total+Other&cons2=PS2&reg2=Total+Other&cons3=PS2&reg3=------&weeks=221

Going by the same comparison of current Wii sales with PS2 sales after the 221st week:

So the Wii needs to sell 10.77M units by this time next year to remain ahead of the PS2 when aligning launches by region. Going back a few weeks to the end of 2010 would reduce that to about 9M units needed.

Thanks Linkzmax. Very informative. I think it is only fair to adjust region launches to coincide. Also it should be noted that PS2 lauched for ~$100 (adjusted for inflation) more than the Wii, so that works in favor of the Wii. It will definitely be interesting to see if the Wii can finish this gen ahead of the over 140 mil the PS2 currently has.

Though, one does also have to admit that this gen, the market is bigger than it was last gen. The Wii may pull off that 140 mill, while never going past the 50% marketshare point. And the Gamecube, or X-Box for that matter, never reached 33.5 mil shipped (where PS3 sits now, even though we have at least 2 more years of this gen to go).