Compared to the farming and industrial revolutions, intelligence explosion first-movers will quickly control a much larger fraction of their new world. He was pro, I was con.
The thesis seems pretty obviously true to me, though there is some issue over how much is "much".
Google or Facebook control a much larger fraction the world compared to farmers or industy folk from decades ago. Essentially technological progress promotes wealth inequality by providing the powerful with technology for keeping control of their wealth and power. So, we have more wealth inequality than ever - and will most likely have even more wealth inequality in the future.
Google's revenues are $29 billion and are dwarfed by such things as walmart ($258 billion) or BP ($308 billion). They are not that important yet.
Link: overcomingbias.com/2011/07/debating-yudkowsky.html