It's disastrous. cDNA is just a direct copy of the most important part of what's in the genomeâ"the actual transcript that gets used to make the final protein. This isn't a victory at all.
I agree that this isn't really a victory. The court still got things very wrong. But the above explanation isn't quite correct, either. The transcript that gets used to make the final protein would be mRNA, not cDNA.
It's still just a copy of the original, though. And a trivial copy to produce. Nature already gave us enzymes to do this, which we isolated from various bacteria (which were also patented). We then mix some stuff in a tube, and voila, we have a complementary copy of the DNA. For a not-quite-apt analogy, it would be like taking a page of text and photocopying a mirror image of it. Or, perhaps more appropriate for Slashdot, transcribing it into ROT13. However you look at it, it is a trivial to produce copy, even if it is sort of a mirror image of the original.
So, I feel that cDNA should not be patentable. It's trivial. It's obvious. It's already existing in nature. Little effort went into creating it. You should not be able to patent fragments of cDNA. Now, how you *USE* said fragments, like as a specific collection of cDNA fragments for a test kit, that's another matter, one which I don't want to get into. I don't like method patents, but that isn't the issue we're discussing right now. The court still got this wrong, due to lack of sufficient understanding of biology.