It's important to remember that no-one could have anticipated a damage of this nature.
Had this been a metal aircraft, it would surely have been damaged beyond repair. But with the 787, the composite structure gave Boeing a change to salvage an aircraft that otherwise would have been written off. And while Boeing have no doubt developed detailed plans for dealing with normal 'ramp rash', this repair has probably been developed from first principles.
So 5 months is not unreasonable, in fact, I think its pretty impressive to think that this frame will be flying again in a few weeks.
This could turn out to be a remarkable testimony to the ability of a composite aircraft to sustain major, yet repairable, damage. Boeing will gain invaluable data on such a repair.
And hopefully a paper will come out to tell the story...who knows, maybe the Discovery Channel is in there with them!