Such a stiff drop of USD/JPY in the short time showcased the world economy is really in bad shape, and the fundamentals of the US economy may be rigged. When equity debacle has no end in sight, investors rash to JPY to protect their assets. In the least, here in China, the economy slowdown is widespread and far-reaching, I don't see any significant improvements in the first half year, even though the financial system pumped up liquidity into corporation sector. I believe USD/JPY will most likely continue falling to 104 level or some, then starting consolidation. The downtrend is quite clear as shown in the chart.