we’re about to find out. Editas Pharmaceuticals is, i believe, the sole commercial licensee by the Broad for CRISPR/Cas-9, and they are scheduled to begin human trials for a rare form of blindness in October.
I would be very interested in knowing more about how Arrowhead Pharmaceuticals compares. The buzzword seems to be "RNA interference", but I don't really know what that means in context.