This sounds like a great conference! Though the distinguished participants have a great deal of wisdom, and I fully support attempts to tackle big questions, the summary reminds me of the limits of this approach. How accurately do you think we can predict where the big advances will come in the next fifty years? Determining which advances in the past fifty years were most important would seem to be much easier, but there would be a lot of disagreement on that question too, even if you restricted the sample to sociologists. Shouldn’t we be a bit disturbed by this?
If you want to take a shot at these questions I’d start by specifying the value of different types of advances, and then outline which type of advances are most likely.