The PS3 has sold 49,519,608 since its launch in November 2006.
Since the PS2 was launched on the 27/02/2000 week (that's 02/27/2000 for you Americans) until the week ending 31/07/2004, that is in the same amount of weeks, the PS2 sold 69,924,823.
Meaning the PS3 has sold 70.82% what the PS2 sold in the same time frame.
I will give you some more data. During the next year PS2 sold about 18m more. It seems that the PS3 will sell at least 15m for the next year if it gets a pricecut, meaning the percentage may increase to 74% or more during the next year. This is speculation though.
Let's assume the PS2 sales stop at 160m. 70.82% of that would be 113m consoles. Can PS3 achieve that? That would put it above the PSX.
Edit: In 5 years and 4 months after launch, PSX had shipped 54.4m units (http://www.playstationmuseum.com/Features/History/History1999.htm), so that would put it at around 54-55m sold in the same time frame. That means PS3 has sold about 91% that of PSX so far. Meaning PSX sales fell quicker than those of PS2. PS3 could follow a similar trend and achieving 91% of the total sales of PSX would put it at 92m. Thanks Carl2291 for this link.
My personal opinion: I was surprised to see the PS3 is doing this well compared to the PS2. I thought the PS2 was more frontloaded than it actually was, but now I see it sold almost half of its lifetime sales after the current generation started. I don't see the PS3 pulling that off, even if the PS4 and X720 come in 2014. For the next couple of years, PS3 may reach 75% of PS2 sales, but after that it should fall much quicker. For that reason I think that PS3 will stop selling at about 90 million.
No troll is too much for me to handle. I rehabilitate trolls, I train people. I am the Troll Whisperer.











