Since Cano had more fielding opps than any other 2B last year, the most accurate fielding metric in comparison of other 2B is UZR/150. While his numbers were still bad last year, they definitely were not the worst. But like I said in my earlier post, Cano, based on Dewan's plus/minus fielding data, was the 5th best 2B in '07. And, other than two month-long fielding slumps last year, Cano's UZR was one of the highest for 2Bs in the MLB (I wish I could find the precise data, but finding sabermetric fielding statistics per month has proven to be somewhat difficult). Therefore, Cano still has a lot of fielding talent, and is still very young. Other than a two month span over the last two seasons, Cano's fielding statistics have been well above average.
However, really what needs to be pointed out is the team's overall upgrade on defense. Based on plus/minus data, the two worst fielders last season on the Yankees were Giambi and Abreu. Both are gone. And even though Cano and Jeter are still there, their CI positions are quite solid. ARod is a solid fielder, and Teixiera is one of the best in baseball (a +24 +/- last season). And, while Wang does induce a lot of GBs, his FB rate is rising annually, making the departure of Abreu a bit more important.
Also, although Wang does induce a lot of GBs, his sinker is very heavy, with a lot of late break. Because of this, the GBs he induces are often very soft. As a result, the whole Yankee infield made more plays on balls in play during Wang's starts than any other infield for any other starting pitcher is baseball (based on Pinto's Probablistic Measure of Range)!