According to Dan Graziano of the Newark Star-Ledger:
Roy Halladay is apparently unhappy in Toronto and has let management know it, and management has apparently responded by doing some quiet surveying of teams (such as St. Louis and the Dodgers) that are far, far away from the AL East in an effort to see what it could get for the 2003 Cy Young Award winner.
Apparently, the returns other teams are getting for top-talent pitchers such as CC Sabathia, Rich Harden and Erik Bedard has inspired the Blue Jays to at least find out what it could get for one of the best pitchers in the American League. It remains unlikely that they’d deal him, but you never know.
Halladay has been ridiculously good this year, and he is signed through 2010 at a below-market rate. Doc is the face of the franchise, though, and if anything the Jays might try to extend him further.