Here's part two of our countdown: 15. Domingo Tapia – If we re-voted on this list today (as opposed to just prior to the start of the season), Tapia would most likely skyrocket into the top 10.  He is absolutely dominating Single-A through three starts, and at this pace will see Advanced-A by the end of the season, although a big-league debut is still a few years away.  He has as high a ceiling as anyone in the organization, including guys named Harvey and Wheeler, and even D3PO named him as a breakout candidate for this season.  He has upper 90’s velocity and a changeup that right now is above average.  So far this year Tapia has been a ground ball machine and is striking out batters at a higher rate than the past couple of seasons. 14. Cory Vaughn – If Vaughn had performed in the second half of last season at St. Lucie the way he performed during the first half in Savannah he would undoubtedly be a top-10 prospect.  Instead, he maintains a top-15 ranking purely out of hope that he can regain the form he had in Brooklyn in 2010 and the first half of 2011 in Savannah.  He has the body size, power, plate discipline, arm, and work ethic to be an above average, if not better, corner outfielder; however, he should have been able to handle a promotion to the Florida State League better than he did, which has brought into question how bright his future looks at the moment.  In Vaughn’s defense, he suffered a heal injury right around the time of his promotion that may have hindered him the remainder of the season.  He is also a diabetic, and 2011 was the first year he had to manage his disease and his body for a full minor league season (not to mention he played in two cities that are very hot and humid in the summer).  So, we may be able to give Vaughn a pass for his performance the second half of last year, but there are no more excuses.  If Vaughn doesn’t play well enough to earn a mid-season promotion to AA his stock will plummet.  Of course, there’s always a chance he can have a bounce back year and get back on track to becoming the player we all hope he’s capable of becoming. 13. Cory Mazzoni – Mazzoni was a 2nd rounder out of NC State in last year’s draft and has pitched well for St Lucie thus far.  He could be a fast riser through the system so a promotion to Double-A by end of the year is a possibility, which means he could be in line for his major-league debut in 2013.  He’s good at keeping the ball on the ground.  He’s always been a starter, but he doesn’t have the ideal size so if he can’t make it as a back-end rotation piece a move to the bullpen at some point is likely. 12. Reese Havens – Talent wise, Havens should be much higher on this list, but he drops a few spots because of all the problems with injuries he has had throughout his career.  Unfortunately for Havens, injuries matter: you can’t develop into a big leaguer if you can’t get on the field and you can’t help out the major league club if you can’t stay on the field long enough to get there.  Both are problems that Havens has.  Outside of the injuries, Havens is a good second baseman with plenty of range; at the plate he’s a guy that gets on base a lot and provides above average power for a middle infielder.  In a perfect world, Havens would already be the Mets everyday second baseman, but in reality he’s inching his way towards the same category as Fernando Martinez: injuries overcoming talent. 11. Jordany Valdespin – It’s starting to look like Valdespin could end up being a very versatile bench player.  His main position is second base, which is a logjam for the Mets right now, but in the past he has played shortstop and recently he has started to learn centerfield.  His speed and athleticism are his biggest assets.  His hit tool is also there because of his impressive bat speed, but he needs to be more patient at the plate and mature in his approach.  Maturity issues have also been a problem with Valdespin, but there is reason to think those are behind him after a breakout 2011 season.