Vid: http://abcnews.go.com/video/playerIndex?id=4738923
Research Paper: http://www.pnas.org/content/102/17/6177.full.pdf
A gene therapy treatment which may increase both cone and rod photoreceptor-based vision is on clinical trial as we speak.
6 children and young people have taken the therapy and so far there is no any notable side effects was noticed.
Very interesting of course, but as you can read it is only specific for a certain type of blindness, caused by a mutation in the RPE65 gene.
This mutation causes a loss in photoreceptor function, but not causes photoreceptor loss by retinal degradation, which is common in many other types of blindness.
So yes, this is definitely promising, but not applicable to all kinds of conditions which cause diminished eye-sight.