Famitsu is reporting a solid PS4 launch in Japan. Sony moved 322,083 of its new systems in its first two days, which is about four times better than the PS3's 88,443 unit Japanese launch.
It's still half the PS2's Japanese launch. It's also roughly inline with both the Wii, which did well in Japan, and the Wii U's two day sales, which went on to do not so well in Japan. So it's not a perfect indicator of things to come, either, but I'm sure Sony is treating it as a win after tripping so hard out the gate with the PS3.