I believe the PS3 will be on sale for that long, however much like PS2 I doubt Sony will be using it as their main console by then, nor will it sell in serious quantities. The price of the PS3 will never drop to the current price of the PS2, simply because it has a hard drive. You can shrink the chips and re-design the powersupplies and circuit boards to PS2 size, however, hard drives have a fairly high base price (relative to current PS2 prices).
Having said that, if a system still sells, even in small numbers, then there is no point in discontinuing it until the cost of supporting it is higher than the profit it brings in. So what if it sells in tiny numbers, if it eeks a profit, and sells enough to retain some shelf space in stores, then let it. Sony needs to recover the most it can from its investment, and given that the PS3 stills sells quite well at $400, it knows there are still consumers that will buy it at that price. Nintendo showed that if you have enough 1st party developers (as Sony does), and you sell the hardware for profit, then you don't need massive market share to get a good return on investment. I'd say Sony last year, after seeing their market miscalculation, started to implement that plan. Sony will try to get the most back from their investment, and come the next console, try again, hopefully with a better understanding of the market.







