OK, I have one speculation:
There, now that Captain Obvious did his work, I'll leave other less sleepy people to carry on the fun and go to bed.
I think the time scar will happen (otherwise it's goodbye to the Impossible Girl and Silence Must Fall storylines, the latter including all of Alex Kingston's appearances and that fixed point at Lake Silencio).
It would seem that either the scar belongs to the TARDIS (with the Doctor and Clara skipping the wait for it to heal) or the Doctor's body really does expire, with a stock solution (eg cloned body, time reversal, massive dose of regeneration energy etc) saving the day sometime after the events of The Name Of The Doctor
. Alternatively - but I think this is highly unlikely - the scar could relate to a far future Doctor, but our Eleven not only gains more regenerations but also time-locks pretty much his entire future, keeping its details out of the scar (and therefore outside the scope of Clara's odyssey through the Doctor's lives, as was the case with most of the Hurt Doctor's life).