[drivebyadvice]

>there is also always the specter of future uses against your interests.

This. The danger isn't even necessarily that we gain some crazy ability to predict things about a person from their DNA, but that people believe that it can be done accurately and that police, courts, government, marketers, etc believe it as well.

Police don't need much convincing if it gets them a conviction. Courts will already admit evidence from forensic labs which have been proven to fabricate evidence. Governments will let just about anything fly if someone donates enough, and if marketers are convinced that it might work, there will be no shortage of cash for campaign funds.

Currently, to my knowledge, you can take somebody's DNA and do just about anything with it without their knowledge or consent, and there seem to be a lot of well-monied interests with a stake in keeping things that way.