Stem cell therapy after latest developments

[knockout maker]

Hi there,
I am wondering, after the latest breakthroughs from past November where Stem cells could be generated from skin fibroblasts just by ectopic expression of three genes, how far are we now to actually repair mutations from affected patients and therefore begin with a sort of "repaired stem cells therapy". I mean, let´s say a mutation is identified in a patient. Stem cells are generated by ectopic expression of these three genes. Once generated, Stem cells could be targeted with conventional targeting constructs to repair the mutation, and that is it. In my opinion the sole obstacle to circunvent at the moment is how to develop a save system, I mean saver that random integrant viruses, to ectopically express these three genes, and then remove the cassette having the three of the genes from the cells. Once this is achieved we could say the era of stem cell therapy has started.
What do you guys think?.
Cheers!!