Erm well, many people may be looking for a new one, due to a recent failure or something. Believe it or not, there are still people out there who have not got a PS2 and will be interested in buying one. It sounds a long shot of course, but Sony are trying to grab the last batch of customers that they can i suppose... It will be these people who are most likely to buy a new version.
There's always a market for this kind of product, however small...