The trade for Carlos Delgado was completed today and in addition to Yusmeiro Petit and Mike Jacobs, the Mets have sent third base prospect Grant Psomas to the Marlins. This is the first I have heard of Psomas being included in the deal, as all prior iterations involved only Petit and Jacobs. Here's a little background.
Psomas was taken by the Mets in the 15th round of the 2004 draft out of West Virginia. Psomas had a breakout year this season, hitting .300/.403/.551 with Low A Hagerstown and then hit .305/.383/.415 in Class A St. Lucie. The numbers, particularly with Hagerstown, are very good. The biggest problem is Psomas' age: he turned 23 in September. 23 is hardly old, but annihilating Low A ball as a 22 year old is not all that impressive. For comparison, at age 22 David Wright was annihilating Major League ball, a full four levels above Psomas.
He has good plate discipline which is something I love seeing in prospects, but he's a marginal prospect at best right now and probably just a throw-in from the Mets' perspective.