[FredSource]

check out www.predictify.com --- might give you some ideas on how to make a buck (and what you are up against!)

[jsmcgd]

Some guy I know is doing the same thing. This validates your idea but obviously also implies a bit more competition. http://www.hubdub.com/

[whatusername]

And for anyone who missed this one lately ---> look at the stakes on this bet! http://www.longbets.org/362

[ckinnan]

also intrade.com is a full-fledged futures prediction market in ireland but may give some ideas.