Not mentioned much in the article: this is far more important in the context of aging than for genetic mitochondrial disease. See:

http://www.fightaging.org/archives/2012/03/a-general-method-...

"A therapy that can robustly correct any mitochondrial DNA mutation throughout the body can be turned into a way to rejuvenate the stochastic damage of aging that occurs to the thirteen important mitochondrial genes not replicated in the cell nucleus. If asked to wager, based on the evidence I'd suggest that mitochondrial damage is the largest individual contribution to aging, which is why it's important to see progress on fixing it or making it irrelevant. So this, I think, is a development worth watching."

Though I believe the RNA-correction methodologies imply some form of continuing therapy to patch the damage versus the SENS approach (allotopic expression and porting back the gene products to the mitochondria) that is a one-time thing:

http://sens.org/sens-research/research-themes/mitosens