The Bank of Japan has taken the era of financial engineering into an entirely new dimension.
Essentially, the policy will entail keeping its 10-year government bond yield at zero. Generally, it's thought that central banks can control only short-term interest rates, but the BOJ believes that its own form of quantitative easing will help control the 10-year and steepen the yield curve — that is, increase the difference between the yields of short-term bonds — which are negative in Japan — and long-term bonds.
One likely side effect of "yield curve control" is that it will increase profitability for banks, which depend on a wider spread in rates in order to arbitrage profits.
Generally speaking, greater banking activity leads to greater economic activity and higher inflation. Regardless, however, most analysts figure the gains in Japan will be incremental.
Central banks around the world have been engaged in an energetic but mostly futile battle to generate inflation. The BOJ's efforts have been on some levels even more aggressive than the Federal Reserve, which has expanded its balance sheet to $4.5 trillion but has been unsuccessful in generating much inflation.