About me: I do have a mitochondrial disease. In some of my cells, my mitochondrial DNA is not complete. If you think about it as a circle, about one third of that circle is missing. It is called a "heteroplasmic single deletion mtDNA mutation".
1. The mitochondrial DNA, much like the nuclear DNA, is a blueprint for building bits and pieces of our body.
2. The mitochondrial DNA encodes parts that are necessary to build the electron transport chain, i.e., to derive energy from food. In the car analogy, it encodes parts of the core engine (spark, combustion chamber, etc); the last step in the whole metabolic process.
3. The mitochondrial DNA does not encode anything outside of the electron transport chain. So, no blue eyes, no blonde, no smart. Nada.
4. This law will allow some kids to have a normal metabolism and a normal life. Nothing more. Nothing less.
5. I am well aware that this will open lots of possibilities for future genetic manipulation, but bear in mind that mtDNA is much more simpler than nuclear DNA and they are two distinct entities, so this law has no application in the field of traditional (nuclear) genetic manipulation.
Hope this helps.