I really don't think the Purple Wedding will be next episode, but on the other hand it would be odd to go so many episodes without an update on Jamie. At the very least I think he'll die in the season 4 premiere. I think we'll probably see ygritte's death and gendry's escape, and they'll spend a lot of time on the RW aftermath, the massacre of Robb's bannermen and the dumping of cat's body. The joff birthday scene will have a lot of time spent on it (giveaway is him saying "I AM THE KING!" in the trailer, he says this in response to Tyrion saying he'll not allow him to force Sansa to kiss Robb's head in the books). Thats more than enough to fill an episode.

p.s. and definitely will end with un-cat.