According to a source referenced to by EspnNewYork.com's Adam Rubin; Jason Bay, Chris Capuano, D.J. Carrasco, Willie Harris and Angel Pagan of the Mets have all been placed on and have cleared waivers. This does not mean that any of the the aforementioned players will be traded, it just leaves the door open for the Mets to move them to a contending team if the right offer is presented.
Since July 31st's non-waiver trade deadline has already passed, the only way for any trades to be completed is if the players involved are first offered to each MLB club by being placed on waivers. If no team makes a claim for any of the players, the team trading the players can then offer each player to any of the other 29 MLB teams.
This is a smart move for the Mets because as of right now, no other players on the team are immovable other than the team cornerstones, David Wright and Jose Reyes. If GM Sandy Alderson is presented with the right offer for any of the players that cleared waivers, it wouldn't be wise at all for him to turn the deal down.