DTV DXing is alive and well; just this summer I was able to receive signals from Milwaukee, WI, Grand Rapids, MI, and Bloomington, IL courtesy of some tropospheric events. My antenna setup is nothing to write home about, either - a Silver Sensor pointed out the ground-floor front window of my house.
There are a couple pages devoted to DTV DX work, mostly with tall antennas, preamplifiers, and low-loss coax.
http://www.tvdxexpo.com/dtvhall.html is one of these pages, with screenshots and distance information.
-Jim