Those PS3 numbers line up pretty well with what has historically transpired in these contests. When Japan picks a market leader, they stick to it, moreso than other territories -- so it doesn't really surprise me to see PS3 sink back to low momentum levels like that. The Wii, on the other hand, is all taken care of for another six months, I think -- it's going to take a while before people get sick of Wii Fit and Smash, and by that point Animal Crossing will probably be out....
Honestly, there's probably not that much that Sony can really do to pick up momentum in Japan again in the short term. In the US, their pricing efforts and BluRay seem like they may actually give the system an extended boost; in Japan, it looks like that boost is already spent and we're back to the week-by-week waiting game for individual titles.
Nice performance by Disgaea 3. This pretty much puts paid to any "shouldn't have gone with PS3!" theories, I think -- it probably would have done worse on the Wii. :lol