L4D2 is about to overtake Uncharted 2 on the sales chart, and it's DEFINITELY overtaken it on the PC/360 sales numbers...so...maybe this is why Valve isn't bothering. When the most vaunted game on the PS3 can only manage these sales numbers, and an "expansion" like Halo ODST topped 4 million this week...what buisness sense if there to dedicate effort to develop for the PS3 from scratch?