National Trust for Historic Places list of most endangered places
The 2011 list is out, see the website, America’s 11 Most Endangered Places.
From the MSNBC article "America's Most Endangered Places":
This year’s list also includes a first-ever “Watch List” designation, assigned to a site NTHP believes faces a growing threat that can be avoided or controlled through collaborative efforts. Its 2011 designee: Charleston, S.C., where the group hopes to promote a balance between the city’s historic charm and its expanding cruise ship tourism. ...
“Sites imperiled by state actions”: According to NTHP, this comprehensive designation refers to the fact that state budget cuts pose an ongoing threat to historic places across the country. If key sources of funding and incentives are lost, thousands of irreplaceable sites and national treasures may suffer untold consequences, says the group.
I think this is interesting, calling attention both to over-consumption and how places can be changed, negatively, through touristification, as well as systemic neglect through budget cuts. Also see the AP story "Charleston warned that cruise industry could swamp historic character."