I wasn't sure if we were supposed to read McNatt's blog or post here! I have a 60 square foot patch of dirt that is my garden, and I have been growing tomatoes for 6 years. The last two years, they were doing the same thing McNatt described - growing beautifully for 6 weeks, then producing a few tomatoes before shriveling up and dying. I thought it was tired soil (these places are 50 years old), but nematodes makes sense. When I pull them out the roots are are clustered. This year, I planted three in the ground and three in pots, and the ones in the pots are throwing out huge amounts of gorgeous tomatoes - Black Prince, Better Boys and Early Girls. The ones in the ground - Black from Tula, Hillbillies, and the grower's special hybrid (all bought at Roger's Gardens) didn't do so well, but the few tomatoes they produced were damn tasty! I highly recommend the Hillbillies, I got six big orange ones before the plant gave up.
I went all organic for the ones in the ground, and all Miracle Gro for the potted ones. Go figure...