It's the sort of news I posted back on Wotmania, but haven't bothered so much here as every other SoIaF post seemed to kick off yet another flame war, which was kind of getting old.

The full news was that GRRM has written two Arya chapters for ADWD which are in the book regardless, taking place after the events of her AFFC chapters. Then he wrote another one or two Arya chapters, one Sansa and two Cersei chapters, all of which were meant for THE WINDS OF WINTER. However, his editor suggested including some of them in ADWD so readers wouldn't have to wait a long time for the next Cersei or Sansa chapter. Due to the current size of ADWD, this plan doesn't seem feasible so it seems to not be happening at the moment.

I'd also argue that whilst resolving Cersei's cliffhanger from AFFC in ADWD might be desirable, Sansa wasn't really in a cliffhanger position so that doesn't seem that important. The AFFC character whose fate most people seem to want to know about (despite apparently hating her chapters) is Brienne.