How will genomes and direct-to-consumer (DTC) genetic tests affect medicine?

The Doctor, Luke Fildes (source: wikipedia)
Recently I wrote about an up-coming roundtable meeting to be held in Wellington looking at aspects of genomics, medicine and law. Over the next few days I will direct a few posts at the subject matter of this meeting.
A visit to the GP, redux
You head off to the GP. They hear your complaints, ask some questions, carry out a few tests. You are offered the remedy that works best for most people.
But is it the best remedy for you?