So Japan's PM says that the country is going to reduce carbon emissions by 2020 to 75% of 1990 emissions [LINK], but is requiring other countries to come along for the ride.
First off, great! It is terrific to see a world leader take a stand and give a real goal... dare I say a target.
Second, this could be a genius move on Hatoyama's part. Japan is pretty amazing when it comes to designing and building stuff, and there is a strong track record of taking ideas/concepts originated elsewhere and making them more useable, streamlined, and efficient (cars, VCRs, etc). So my first take on this is that Japanese companies like Toyota and Mitsubishi ( cf.) are going to have an obvious target for building efficient things (things of all kinds!). These companies already have a head start down this path, and having a huge economy destined to reduce emissions means there is economic incentive to improve R&D.
If these companies, which are already leading the world, now accelerate their R&D, they will be selling their wares to the rest of the world shortly. This will be especially true if Hatoyama gets his way and other countries do vow to reduce emissions. If Japanese companies can do for power generation what they have done for other industries, then the whole world will be buying Honda wind turbines and Sony solar panels in now time. (possible example) What a boost to the Japanese economy! Wish the USA could have thought of that.