I would add that there is value in being able to link with other carbon markets. The world's largest carbon market is currently in the European Union, and the European Commission has made it clear there wouldn't be any possibility of Canada being able to link to the European market if we have intensity targets.
But I think the biggest problem with intensity targets is that they have a track record of abuse by governments. We've seen the intensity targets for greenhouse gases set by the Bush administration and by the Government of Alberta, which have been presented as representing major steps forward, as major emission reductions, whereas in reality they allow emissions to continue to increase.
We need targets that can be easily understood by everyone; that are related to the environmental goal, which is emissions, not emissions intensity; and that maximize accountability.
If the government wants Canada's emissions to continue to increase, it can still set absolute targets, but at least everyone would be clear as to exactly what was intended.