Rafael DePaula may be the best pitching prospect in the entire Yankees system if you consider just his raw mechanics and "stuff" and exclude all those years spent trying to obtain a visa to come to the United States. DePaula has a pitchers dream frame standing 6'2" tall and weighing in at 212 lbs so he is very project-able and looks like he can be very durable while throwing heat for the foreseeable future hitting 92-94 mph on the gun but can hit 97 mph.
Rafael DePaula will be entering his age 23 season when he starts the 2013 season in the Dominican Summer League for the Yankees. DePaula sits comfortably at 92-95 mph with his fastball but can dial it up to as fast as 97 mph when he feels it necessary. He has the secondary pitches to go with it to make him a successful major leaguer including a curveball, a slider, and a change up that are all considered raw but plus. He is going to move fast through the Yankees system in my opinion because his stuff is just too good to hold him back. I expect him to be stateside by the end of the 2013 season.
ETA: Late 2014 to Mid 2015