It's been close to a year since ABC7-KGO in San Francisco launched their prediction marketplace. They recently did a story recapping their experiences here.
It's not deep on details but I like in the video how they represent the probabilities of things occurring by adding "chance" to the numbers. It makes it clearer what results coming out of the markets really mean vs. a black & white right/wrong.
Also, I didn't realize until recently that Eric Zitzewitz, the Dartmouth/Stanford Professor and prediction market guru was their top trader at over $1M. Nice job, Eric.