"Scientists Announce HGP-Write, Project to Synthesize the Human Genome":

The publication occurred on Thursday by the journal Science.

The authors of the proposal said that the ability to fabricate huge stretches of DNA would allow for numerous scientific and medical advances. It might be possible to make organisms resistant to all viruses, for instance, or make pig organs suitable for transplant into people.

The project, which will be run by a new nonprofit organization called the Center of Excellence for Engineering Biology, will seek to raise $100 million this year from various public and private sources. Organizers declined to state the ultimate cost of the project, though it could conceivably exceed $1 billion....The organizers of the HGP-Write project hope to do much the same with DNA synthesis, reducing the cost more than 1,000-fold in a decade. Still, even if such progress is made, it might cost several million dollars in 10 years to completely fabricate one human genome.

...But George Church, a professor of genetics at Harvard Medical School and one of the organizers of the new project, said that if the changes desired are extensive, at some point it becomes easier to synthesize the needed DNA from scratch. “Editing doesn’t scale very well,” he said. “When you have to make changes to every gene in the genome it may be more efficient to do it in large chunks.”

I don't think I need to elaborate on the importance of this, here.