I think a lot a focus is being put on how much it can hurt speakers and weed out bad ones rather than how much it can help. I just spoke at WordCamp Baltimore last week and was on a Panel in Philly last year. Both times I think I did well I got a lot if great feedback in Baltimore but I have no solid numbers to show for it, nothing to present to the next WordCamp I may want to apply to. I think having a repository or reviews for organizers and even public to see would be great to help those that may not speak often but are good. Also for new speakers seeing what audiences looking for will help them see what they are up against how to structure their speech etc. yes there will be some who are scared away but maybe they aren't ready.