Carlos Beltran is one of the hottest names on the trade market because he appears to be the biggest bat that will be available. As a result, there are plenty of teams that will seek to add his services for the stretch run as they compete for a Championship, which means that the Mets will be able to ask for a pretty high price for their high-priced slugger.
One of the teams that makes the most sense is the San Fransisco Giants, but according to MLB Trade Rumors, there seems to be a philosophical difference in what they are willing to offer vs. what the Mets are requesting.
San Francisco is willing to take on most or all of the $6MM or so remaining on the outfielder's contract, but won't part with a high-end prospect. The Mets are willing to absorb salary, but are insisting on high-end talent in return for Beltran.
Other teams that are interested in Beltran and would make a trade if they have the prospects that the Mets covet are the Phillies, Brewers, Braves, Red Sox and possibly the Yankees. Beltran will be on the move, but as of now, where he ends up going is anyone's best guess.