If we can look forward to them splitting the pacing up to half a book per season, that'll be...what, after this season, three years? Then again they've also jumped to Theon's fate, which is very much a book five thing (Shit are they just going to be torturing him for the next two seasons? They already took his Kraken!). Presumably this season's central events will be the Purple Wedding, the trial of Tyrion Sansa in the Vale, the battle for the wall---maybe meeting Coldhands? Oh we get Leaf this season, I think. And since A Feast for Crows is occurring through roughly I think the first half of A Dance with Dragons(?). Ugh it's tough to figure out how it's going to work book-wise when the show occasionally just throws whole stuff from the books out the window. We've already got Daenerys on the throne of Meereen, by the looks of it, as well as what looks like the assassinations from the sons of the Harpy or whatever, which I think is occurring around the time of AFFC. I'm pretty sure this season's big ending twist-hook will be Lady Stoneheart, but time and place are pretty scrambled in my head now.
If this season is already edging into AFFC/ADWD events (Dany on the Meereenese throne--sons of the Harpy assassinations, Theon getting more torture :< ) I think the season after this one we might get Jeyne Poole!