spoilerfix said that it will basically be a two hour Desmond flash back.
I think the boat is the one from last years season finale. The others sent it there to remind Walt what has to be done. I think he got the boat for killing Ana-Lucia, it wasn't said straight out but it was implied.
I can't wait to see what Walt does. He said the others were pretenders. I really hope they explain that this season.
