Its the same as the late blight of potato fame. I'm not sure of the extent of the spread of it but my mother gardens in the Atlanta area and she has no problems. I know its an issue in western canada as well as throughout the Pac NW. Water hitting the leaves is what facilitates the blight as I guess the spores are everywhere already waiting for an opportune moment to grow. I saw an article in Time (or Newsweek) that discussed the search for the original strain of blight from the potato famine. I guess the theory is that finding this strain will lead back to its source which may yield some native potatoes in S. America that are blight proof - then the blight proof gene can be bred back. It also mentioned that the tomato late blight had reached epidemic proportions but didn't really elaborate. Given the very suspect nature of Time and Newsweek reporting, this is almost guaranteed to be an over simplification that doesn't really jive with the facts. My tomatoes will be blight free as long as they aren't exposed to rain or overhead watering. Unfortunately for me, strong winds this spring ripped off my temp plastic tent and my tomatoes are exposed to rain as we speak. Deep sigh. There was mention on the PNW garden list about the development of Legend, a tomato bred to be resistent to late blight. Maybe others on this list know more. And to the list owner, much to my surprise my husband (who is a private pilot) told me he thought Ferndale did have an airbase here years ago over next to the Puget Sound at Cherry Point. Teressa in Ferndale where my garden is getting a good soaking today.