Based on previous information and not just this one post in isolation, that means one of the four majorly problematic chapters that make up 'the knot' is now dealt with. Of course, GRRM's disinclination to give updates since November means that progress could have been made on the other three as well. Beyond that it is unclear if there are more chapters that need finalizing beyond the knot, and there is still the matter of the completed Sansa and Cersei chapters that GRRM and his editor are pondering should be in ADWD or Book 6 instead.

Of course, the update doesn't give us much concrete information for deriving a completion date, which is what a lot of people are after, only that it's inching closer.