Canada's Task Force on Spam releases report
Canada's spam task force recomends a number of inititives, including some new anti-spam laws. They recognize that a coordinated effort is needed. It includes an interesting chart showing spam trends and the impact (usually temporary) of attempts to control it. I believe spam will only be reduced as the risk/reward ratio changes. In other words, the financial gains of sending spam must become less than the costs (both in actual dollars to send, and the legal risk of sanctions.
We can do our part by using filters and deleting what comes through.