They do but their aging and their farm system is not so great.
Not true. They don't necessarily have any "holy shit" prospects that the rest of the MLB is drooling over, but they definitely have some able-bodied hitters in their lower ranks:
Joshua Satin (25 years old, .308/.395/.472 in the AA Eastern League last year)
Zach Lutz (24, .289/.389/.578 in AA Eastern League)
Lucas Duda (24, .314/.389/.610 in AAA International League)
Nick Evans (24, .300/.371/.536 across AA-AAA)
Ike Davis (23, .261/.351/.440 in the MLB)
*All players had at least 300 PA's last season, and all leagues were roughly 4.5 R/G environments (the MLB is a 4.38 R/G environment).
And it's not like they have a glutton at one position, either: Davis is a 1B, Evans can play both corner IF spots and perhaps some OF, Duda can be a 1B as well as play both corner OF positions, Lutz is a 3B and Satin is a 2B. On top of that, Cory Vaughn (21, .307/.396/.557) and Darrel Ceciliani (20, .351/.410/.531), both OFers taken in the 2010 and 2009 MLB drafts respectively, absolutely tore up low-A ball in 2010, and both of whom were under the league-average age (21.1) in a 4.49 R/G setting. It remains to be seen whether they will be fast-tracked by the Mets, but their level of production so quickly after being drafted, albeit in one of the lowest rungs in the minors, is intriguing.
As for pitching, they also lack huge prospects, but three pitchers do stand out:
Manuel Alvarez (24, 0.872 WHIP and 9.50 K/BB in AA last season)
Mark Cohoon (22, 1.079 WHIP and 4.09 K/BB across A-AA)
Yohan Almonte (20, .926 WHIP and 4.00 K/BB in low-A)
*All pitchers had at least 75 IP's last season
So, are they overflowing with can't-miss prospects at every position? No, but they aren't exactly hurting either, and they are at the very least in a vastly superior position to produce regular MLB players than the Sox' system.
It might take a few years to get over some bad contracts--Jason Bay is getting almost a $10 million raise starting next year and isn't going anywhere without his consent. But really, Bay is one of very few long-term horrendous payroll hogs for the Mets: K-Rod, assuming they can't void the rest of his deal, is conceivably done after next year along with Carlos Beltran, Oliver Perez and Luis Castillo. They might have to bite the bullet and either pick up Jose Reyes' $11 million 2011 option or extend him (which could be pricier still) and hope for the best, but yet they might have some wiggle-room in this upcoming off-season (depending on what happens with K-Rod and Reyes), and will definitely have some freedom after 2011.
Going to the Mets could actually be considered the best option for Hahn, seeing as how he is not too bogged down by horrendous contracts paid to bad players and has a seemingly capable stable of prospects that could at the very least be used as stop-gaps until the team reaches financial freedom after 2011. And if only a few of those prospects pan out into average-to-above-average MLB contributors, the Mets could turn back into a contender in short order under Hahn's direction.