Dead Island Riptide is a spin-off of the original zombie resort simulator. Publisher Deep Silver is very clear to point out it is not a sequel, so think more Assassin's Creed: Brotherhood or Halo 3: ODST. Riptide was announced this summer, but now we have some more details.
The game will return the focus to close combat from the latter gunplay found in Dead Island, with a new weather system and upgrades to the engine of the first game. The weather system will now include flooding and lovely trips down zombie infested rivers on little boats. There are also forts that need to be reinforced and barricaded.
Players will be able to import their character stats from the previous game, but the new game takes place in a new location. It's the same archipelago, but not the same island. The game will launch in 2013.