LAST EDITED ON 04-13-10 AT 12:56 PM (EST)LOL! No, they didn't drown. Like QL every episode of TTT ended with a cliffhanger jump through time. "Oh, boy!" The final jump back to the Titanic was the end of the series after an adventure set in the future. But it doesn't make any sense looping back to the pilot episode, it's a paradox since the time travellers started out at the project and originally made separate jumps to the Titanic (the first jump was an accident, the second an attempted rescue).
It would have made more sense to have them end up on the Britannic trying to prevent her sinking.
I'm really hoping that wasn't foreshadowing as I would like "Lost" to have a satisfactory conclusion. (That said, as long as they resolve the mystery of the island itself, anything else is fair game: An open-ended conclusion wouldn't ruin the series.)