When Michael made the deal to bring back those people on the list, he told the woman he wanted the boat. That's the only tie in I can see.
And yes, Micheal is creepy. I know he wants his boy back, but do you kill and deceive to get him? What does he do once he gets Walt back? Sail off into the sunset on that little boat? And that's assuming the "others" keep their word. All indications throughout the series have been that Walt has some special powers they're interested in. Henry said they'd never give him up. I'm looking forward to the season finale but I'm sure that even if we get answers to some of the puzzling plot twists it will leave us with a lot more unaswered questions.