There is a fairly good article about the the potato/tomato blight sweeping the Northeastern U.S. in last Sunday's New York Times. I was just there, and the damage is devastating for many small potato farmers. In my opinion it even more devastating for the area's many small diversified farmers, many of whom are beginning farmers.
This is because, unlike many of the potato growers, they will never recover their lost income (and so much of the direct sales in farmers markets are tomato sales at this time of year) through the federal disaster programs that the potato farmers are able to take advantage of.
The author incorrectly identifies the pathogen responsible for the damage as a fungus. Although it is fungus-like, the pathogen is actually Phytophthora infestans (which causes the disease late blight), which is not a fungus, but an Oomycete, which, though it looks similar, is actually biologically very different.
Here in Michigan, and throughout the Midwest, the tomato crop has been terrible this year as well, not because of late blight, but because the cool whether has significantly delayed ripening. This is especially problematic for many of the heirloom varieties that direct market growers produce, because they take so much longer to produce.
The New York Times article does point out, correctly in my opinion, that planting a diversity of tomato varieties, some hybrid, some heirloom is a good way for a small direct-market farmer to hedge their bets in a year like this. The author also points out that by cutting Extension and traditional breeding programs, we have greatly reduced our ability to deal with these things, though he doesn't mention that the reason traditional breeding programs have been cut so sharply is because so much money is now focused on genetic modification, rather than traditional breeding.
I have a lot more to say on many aspects of this issue but will leave it to your comments or questions to direct further discusssion (simply hit the comment link at the top of this post). Here is the link to the NYT atricle: http://www.nytimes.com/2009/08/09/opinion/09barber.html