Similar to the 7 States of Facebook which surfaced a few years ago. http://gigaom.com/2010/02/08/the-7-somewhat-united-states-of... Culturally some of these boundaries seem more accurate.
My takeaway from the "Nine Nations" map is that it was created by people that have never actually lived or spent significant time all over the regions of the US, never mind North America, to have a frame of reference for the actual cultural differences. Some of the supposed cultural similarities are apparently based on popular caricatures of the rest of the US I see in places like urban New England. You can carve up North America on major cultural boundaries but it looks a lot more like the Facebook map.