At JoeTheBro: You see it a little wrong. From the 150 M userbase from the pS2 there arent many people left which buy games for the PS2 anymore.
From the 70 M + userbase from the pS3 there are many people which still buy software for the PS3 and will not upgrade to a PS4 the first day.
Plus there will be many people which buy a PS3 at a low price point.
The PS3 still has the opputurnity to sell another 20 M units if handled right.
It would be insane to ignore this market.