Myriad: does it make a difference in the real world?

The IPKat is always pleased to receive an email or two from a respectable source, so he was delighted so receive the following brief and to-the-point message from Professor Sir Robin Jacob, helpfully signposted 'IPKat Question' in case its recipient should mistake the sender's intention. It reads like this:

Does Myriad [see earlier Katposts here and here] really make a difference? If you can have patents for cDNA consisting of a gene code but not the isolated gene (with its introns) what difference does that really make in the practical world?

Sir Robin is talking here about the world in which business decisions are taken, new products tested and marketed, investments placed and scientists employed; a world in which manufacturers vie with one another for commercial advantage, and in which patent owners tiptoe through the minefield of prospective patent litigation, regulation of healthcare products and antitrust and abuse of monopoly.  What does the ruling in Myriad mean in this world?  Answers, please.