While some say its nothing more than changing the battery in a radio, (the power source of an embryo being the mitochondria)It still requires (or should require) wrestling with the implication of the establishment of the ability to clone a human in the future to whatever specifications are desired.
To be honest I personally don't become overly worried when discussing the desires of two parents. The greater and more worrisome implication will be the ability of other entities, 'Big Brother", NeoFacsists, ChiComs, or WalMart to clone off whatever humanotype needed for a specific job, task, organ bank, or secret shopper program.
There is the concept of the "slippery slope" to consider. If a well intentioned researcher can figure out how to reduce the risk of mitochondrial disease by this method can the "evil doers" be far behind in finding a nefarious purpose for it?