It's a low-risk situation for the Yankees, and Jones will probably just ride the bench most of the year and fill in here and there for outfielders or DH's who get hurt. It's been 5 years since Jones has hit over .250, so the Yankees can't be expecting too much out of him.
Not to mention many players can't handle the pressure in New York like they could for their former teams and their numbers plummet. Jones' also has been on the decline for quite a few years now, so that does not bode well for him either. He could end up being a decent pinch-hitter for when the Yankees need a home-run in the 8th or 9th inning.
By the way, don't forget that the Yankees are the most successful team of all time and they always find a way to win. Oh yeah, and who is snubbing the World Champion Giants around here? There are many strong teams on paper, but what defines a champion is he who wins it on the field.
Its a no risk all reward if he has 30-40 rbis and 10-14homers the he pays off because he will only get so many at bats. Jones had a decent season last year hit 19 homers and 48 rbis thats not to bad dispite the 230ba.