The models keep showing this as a possible threat. Jeff mentions his reasoning for the ice potential in the winter pattern thread. A very strong cold front will sweep through the area overnight Saturday into Sunday causing crashing temps. Most models agree there will be moisture of some amount behind the front. There could also be freezing issues due to the heavy amounts of water left by the rain.
In addition to the totals of ice below. Models also show some degree of sleet or snow. I believe the Euro showed an inch or so in a good portion of the area. The NAM shows some snow in parts of East Tennessee. The GFS had a couple of runs showing it too. I believe some of their maps may be incorporating sleet into their snow total maps.
The worst case scenario is the Canadian, crippling ice storm for a good portion of the Valley on the 12z run. The Canadian was the first to show this possibility and hasn't wavered from it for days on end.
The GFS is much more localized with freezing rain totals.
The NAM splits the difference.