This is a great idea. One of the major challenges about making event surveys is making them scientifically valid. It is easy to make surveys that sound like fun ("What did you think of the talk? Mind Blown, Awesome, Decent, Didn't Like It, Bleah") but these are not useable in a statistical way. Proper surveys are dry and without personality for a reason and that reason is accuracy and an avoidance of bias. Having the surveys centralized means all WordCamps will be measured with the same stick so to speak and you don't have to have a social scientist on your planning team to get accurate data. I'm all for it.