While there are many homebrewers who are willing to fly around the country to attend the NHC conference, I would argue that there are many more that would attend if the conference is within driving distance. So the above map gives an idea of whether the yearly conferences doing a good job covering the US population as well as if there are highly populated areas that are being left out.
Of course, the above logic is based on the assumption that the general US population distribution is equivalent to the population distribution of US homebrewers (which may or may not be a valid assumption). And while I may also be a bit biased (being a New Englander), it seems that much of the Eastern Seaboard and the Pacific Northwest have not been getting a lot of love from the national conference.
Obviously a lot more goes into the conference site selection, including a well organized hosting homebrew club, affordable accomodations, and a thriving beer scene. This map was just another way to look at where the conferences have been located and how it relates to population densities. I am sure I am not alone when I say that I am very interested to see where NHC 2012 will be hosted.
"An honest brew makes its own friends."