I don't have any experience with Tennessee, but I can tell you from experience out here, once they get a foothold, there is no stopping them.  We have never had them this far south in California, but about 4 years ago, a local Indian tribe released 7 or 8 of them to try and establish a hunting program.  Problem was, they have no fences, and border national Forest land.  Needless to say, they reporduced and moved out. 

They now estimate that in only a couple of years, the population has gone up to 500-1000.  They can't get a great estimate due to the rough and thick terrain, but there have been sightings over 20-30 miles.

Watch the Nat Geo show "Pig Bomb" if you can find it.  Great info. 

I live and hunt in Montgomery Cty, Tn. I've never seen a wild hog to this day in the county any place I've hunted. I do hear stories of people seeing snd shooting them, but as much time as I spend afield, I'm still at zero sightings. I do hunt a stretch of river bottom (Cumberland River) land surrounded by some pretty good agriculture, just south of the city limits, but nary a sign of them there along the river either.

I'm anxious for them to start showing up, knowing they are very close to some areas I hunt. I am also pretty sure the local farmers are not quite so interested in seeing them. Many years ago, while hunting Westvaco property in Stewart County I came across a big hog dead alongside a logging road. At the time I thought perhaps someone had simply dumped a dead farm hog, but who knows. As much $$ as I spend hunting hogs down in Georgia, it might be nice to seem some "locals".

There are a good number of coyotes in the area, as you have surely seen. I only take them incidental to deer hunting though. I'll also admit to not shooting several I could have, not wanting to make commotion during a quiet morning's deer hunt. The last one I actually tried to shoot was late '08 and I was hunting the river property. I saw a big buff colored male loping down the field I was looking over, with a female in trail behind him. Big and with that very odd color, I decided to take a shot at him with my M/L, wanting that special hide. I whistled to get him to stop, as I'd learned to do with others I'd whacked. Except, apparently this one had been whistled/shot at before because the moment he heard that whistle he shifted from 4th to overdrive! The female did pause for a moment, but I was not even tempted. I had to laugh at myself as I lowered the unfired M/L.