I think before the release of any new technologies we should understand the implications of those technologies.
I don't think we can ever actually know what will happen down the road. We have to balance the future implications of something we can't predict with what we want to get done today. I think the precautionary approach essentially suggests that we need to err on the side of precaution: don't jump into something if we haven't done enough studies.
That's not to say we should spend 50 years doing studies, but we should probably spend more than ten years doing studies on things that have lifetimes of replication and genetic modification potential. We need peer review trials. We need studies that come from other people than those who are developing the products.