Slippery slope. They are marketing it as curing diseases before they can happen, but man would not be content with that and would continue to push the envelope and like Ma said, then you've got a menu of options for your new designer baby.
Now they want US public funds (your tax dollars at work) to fund further research on human embryos. These "embryos", btw, will be "disposed of" after testing. Don't let the fancy words get in the way of the facts here.