I don’t actually see any change in policy here, just new rhetoric. A colleague sums it up:

Bush’s remarks closely follow Bjorn Lomborg’s recommendations in his recent Congressional testimony. Most of the speech calls for elimination of trade barriers and support for programs to reduce AIDS and malaria in developing countries. The climate change part calls for commitments to invest in clean energy and for each major emitting country to set its own long-term GHG reduction targets with mid-term performance reports. The most objectionable part is the blather about the 35 billion-gallon renewable fuel mandate.

Indeed. He is calling on the 15 big nations to get together and agree to…do their own thing. The renewable fuel mandate is, however, positively harmful and should be objected to in the strongest possible terms.