I'm not convinced that "policymakers being better informed" will really make the world a better place. They will still tend to act in their own best interest.
What makes a difference is the public being better informed, and holding their (elected) representatives responsible for their decisions. At the moment the voting public in the western world is not particularly well informed. Not that there isn't enough information out there, but that the average person isn't exposed to it or doesn't seek it out.
That said, I am interested in an exchange of this sort, as a gambler rather than as a humanitarian.
Intrade is another example of a site that does some of this.