Ken Rosenthal has a little Phillies tidbit in his latest piece for FoxSports.com. Rosenthal reports that the partial no trade clauses enjoyed by Roy Halladay, Cliff Lee, Ryan Howard and Chase Utley all enable the player to block deals to 21 teams per season. Not that the Phillies are contemplating trading any of the four players -- at this point, Lee is probably the only player whose contract could be moved -- but the detail does show how difficult it would be to trade any of the four players even if there was a market for their salaries (and talents).
The way these things usually work is that before the season, the player and his agent submit their list of teams to which they will block a trade. The way to preserve the highest amount of leverage in any potential trade talks would be to block the 21 teams with the highest payrolls, because it is hard to imagine any of the nine lowest-spending teams taking on big money, particularly when you are talking about Howard and Lee, whose deals will pay them more than $20 million per year through at least 2015.
Again, the Phillies have given no indication that they would shop any of those four players. As Rosenthal notes, Cole Hamels and Shane Victorino would be the two players most likely to move in a sell-off. But I don't see that happening unless the bottom really falls out.