Digg-style voting to choose questions for Presidential debates?

There have been interesting calls from a prominent group of Internet movers and shakers for questions at future debates between McCain and Obama to be decided by an 'open' system of voting, rather like Digg.

On the face of it, this would be a more democratic way to decide the agenda for the next set of debates - an agenda which is currently being decided pretty much at the whim of the media host.

But given the efforts that some people put into spamming links into Digg, perhaps what this would really do is hand control of the political agenda over to a cabal of social media professionals.