Columbia University statistician Andrew Gelman is not impressed:

The 50 states don't vary much by life expectancy, literacy, and school enrollment. Sure, Hawaiians live a few years longer than Mississippians, and there are some differences in who stays in school, but by far the biggest differences between states, from these measures, are in GDP. The average income in Connecticut is twice that of Mississippi.

To check out the relation between HDI and income, I loaded in the tabulated HDI numbers and plotted them vs. some state income numbers ... The correlation between the two rankings is 86%...

I think they should've just gone with the traditional measure of human underdevelopment in U.S. states: distance from the Canadian border.