Haven't read Guns, Germs and Steel myself, but "why and how European civilizations were able to conquer technology and the world, and specifically why many of the developments critical to the rise of European supremacy are not found in other societies" sounds like a description of "Civilisation" by Niall Ferguson.
Ferguson is someone whose contemporary political writings have really pissed me off, but his longer-view historical works (I've read The Ascent of Money but not yet Civilisation) are fairly insightful.
Yeah I've read The Ascent of Money too, it was great. You'll enjoy Civilisation.
Although after learning of his political views(I don't live in the US), I couldn't help but wonder how much it influenced his views in Civilisation. It comes off as a bit overly biased in favour of Europeans (read: the white man) when seen in this new light. For example, he tries to argue that church attendance being down is a sign that European influence/culture is declining.
http://amzn.com/0143122061
(Niall Ferguson is pretty outspoken politically too, e.g. http://www.theatlantic.com/business/archive/2012/08/a-full-f...
http://blogs.telegraph.co.uk/news/timstanley/100177487/has-n...)