DO you think that should be the only legal use for this capability?
Or do you think that, once it is perfected, that parents should be allowed to use this or other genetic techniques to manufacture their children any way they want?
How about this question: Should deaf parents be allowed to take positive steps to ensure that their children are deaf?
If we found a gay gene (I know, this is a hypothetical question) should gay parents be allowed to force it on their children?
Stepping back from those specific questions — do parents have the right to dictate the genetic makeup of their children?
Just like any other form of evil, once the gate is opened ever so slightly it becomes nearly impossible to close.
This technique has no possibility of being used to manufacture children with specific traits, other than being free of mitochondrial disease. All specific traits are coded on nuclear DNA and heritable from either parent (except male gender, which requires the Y chromosome from the father). Mitochondrial DNA is an entirely different thing.