@ Robjoh
I think with regard to PS2 hardware sales the Japanese market may have hit a point of market saturation (Japanese gamer penetration), but globally new PS2 hardware sales still seem to be outperforming Nintendo Wii hardware sales so far. With regard to new Japanese software sales the PS2 still leads over the Nintendo Wii, but if you look at Famitsu's gamer wishlist it's dominated by major PS3 titles, so I think when they are released the PS2 hardware sales will steadily decrease and PS3 hardware sales will steadily increase in course of time.
Currently there's not that much of interest within the PS3's software library for Japanese gamers, mainly Gundam Musou so far which sold much better than any XBox 360 game released in Japan so far, despite the platform's one year headstart.
