First, I don't think a judgement about the Sox or the Yanks can be made before the trade deadline. They both have holes to fill, and the team dynamic can change drastically with some new faces. Remember the Red Sox last August?
Second, the next month will be a big determinant on the Yankees chances. Just look at their schedule:
July 7-10, CLE (46-38)
July 14-17, @BOS (48-35)
July 18-20, @TEX (43-40)
July 21-24, @ANA (52-32)
July 26-28, MIN (46-36)
July 29-31, ANA (52-32)
Aug 2-4, @CLE (46-38)
Aug 5-7, @TOR (43-41)
Aug 8-10, CWS (57-26)
Aug 11-14, TEX (43-40)
If they can keep winning through that stretch, then we can't write them off.