Over at Fangraphs, Jeff Sullivan posted their 2015 UZR projections by team. The Yankees, who were an average defensive team last year, project as the 3rd best team in the majors in 2015 at +29 runs, in large part thanks to the additions of Didi Gregorius and Chase Headley.
Of course, that +29 number is highly regressed. The 3rd best team in 2014 ended up at +49 runs, or just over +6 wins above average. If the Yankees are that good defensively, they could make a lot of contact pitchers look pretty good next year. It might even make the team good enough to be a stealth contender for a wild card spot.
The full rankings: