The first two years that the PS3's has been out it sold 18 million (almost), and thats with an average price price of $500. By 2009 there will be a price drop to $349 and even possibly to $299. Do you think that that Sony will sell 100 mill+ PS3's by christmas 2011 not to mention in 2009 they will have the best line-up avalible IMO.
EDIT: I say 2011 cause that would be at least 5 years into ps3 life