This may come as a disappointment to last-gen gamers, but it's sounding as though Assassin's Creed: Rogue will not have multiplayer.
In the latest issue of Game Informer, the magazine states that Rogue is "single-player only," though it's a tad bit unclear if they are referring only to the campaign or if Ubisoft has decided against offering a competitive mode. Should it be the latter, this would be the first time a core Assassin's Creed title wouldn't have a competitive multiplayer option since prior to 2010's Brotherhood.
It's possible that Game Informer is referring to co-op multiplayer, since Unity for Xbox One and PS4 will give players the option to play certain missions together; but, as we learned earlier, Assassin's Creed: Unity will also be skipping competitive multiplayer, so it looks like Ubisoft could pass on online gameplay all together with Rogue. With two Assassin's Creed games due out this year I wouldn't be surprised to see them skimp out on some features for the last-gen version.
Assassin's Creed: Rogue was formally announced yesterday. It's coming to Xbox 360 and PS3 this November, and will star Assassin-turned-Templar Shay Patrick Cormac who will travel across North America, from New York to the frozen North Atlantic, to hunt those previously called brothers.