Prediction Markets on the Intranet

I had a long discussion on prediction markets today. I'm convinced that internal markets are a great tool for intranets: Test products, test ideas brought up through innovation management, give employees a sense of participation, gambling and of a chance to get in the spotlight ( - "I was right").
Mandatory prerequisites are:

• a decent usermanagement that does not add any hurdles
• an integrative intranet-environment
• a media landscape that offers more participation opportunies (wikis to start, discuss and sharpen ideas, polls to get through the first steps of idea-casting, posting and commenting-opportunities)
• an open and supportive company culture
• some sense for competition
• a moderator/admin who can get things going

The preprocess - how to find the right questions to treat on the markets - is even trickier to me than the market itself (especially regarding innovation management, bringing up, evaluating and trading ideas). I'm still looking for great examples in that area.