140,000,000

I have a launch PS2 which i use almost everyday, and i will be buying another PS2 slim when it drops to the $99 pricetag.

140-150 million. 

120 million unless they already shipped more.

 If it was a £50 I might consider buying another slimline, but I dont expect the price to go below £75 in the UK

I think i will agree with leo-j and say about 150 million will be where the PS2 will end up :D

135 million, 140 million max. Another 35 million is impossible for a dying system, even when it still has another pricedrop.

 You'd be surprised. There are a lot of people out there who aren't really into videogames (other than the Wii perhaps) and -when- Sony drops the price to $100, and with the still growing library of more casual games, it will still be a very attractive choice.

148m

125-135 million sold.... remember people, the 130 million shipped is using Sony's old method which counts the many PS2s they handed out as replacements for early models.... I too suspect VGC may be low, but firstly I have nothing to base it on and secondly i would guess only 2-3 million undertracked (so 118 million, which probably means 120-121 million retail shipments)

Possibly 145 million at the price tag of $99.99/€99.99/£69.99/¥12,000 (or lower).

Sony has just released the new 90000 model with integrated power adapter in Japan. With the way that Sony keeps improving PS2 and promoting the 40GB PS3, I won't be surprised to see Sony releasing a 720p/1080i upscaling PS2 in the near future. If that happens, PS2 sale can easily go above 150 million.