The Yankees are 10 out in the loss column in the East right now. They are playing very well though. They've won their last 5 in a row and the next 5 series they play are against the D'Backs, Mets, Rockies, Giants and Orioles. Boston is obviously playing well as they have been all season, but if the Yankees can keep up this good play against those opponents and get within, say 6-7 games of Boston by, say, even the All-Star Break (Really, is it that inconceivable? Think about it.), you're going to tell me they still don't have a chance at winning this division (or at least making it very interesting)?
Sure Boston has a major upper-hand, but I think we should be able to determine that they're dead in the division before we ask if they'll finish .500, and in my opinion, we cannot do that yet. Even if they were to lose the division, they are still very close in the wild card chase. The Yankees baseball season is far from over right now. Maybe this year will just be a lot more interesting in August and September than it usually is, though.