As of now, A.J. Burnett, Antonio Bastardo, Ryan Howard, Kyle Kendrick, Roberto Hernandez, Marlon Byrd, Jonathan Papelbon, Jimmy Rollins, Chase Utley, Cole Hamels and Carlos Ruiz are all out there on waivers, waiving around.
Every year we go through this, and every year we are assured that generally, this process is at least little or nothing happening, and at most shadowy manuevering after which little or nothing happens. But that doesn't mean it's not complicated.
A player put on waivers is dangled by their current team, fully vulnerable of being claimed by any team who wants them. However, upon being claimed, that player can be pulled back by their current team (only once, though), and nothing changes. But if the team really wants to get rid of the player, they can just let them go, and the team that claimed them absorbs their full contract. This almost never happens. It will definitely not happen to Ryan Howard.
The third thing that can happen is the player gets pulled back, but their current team, upon realizing the previously secretive interest the claiming team had, works out a trade so that they can get something back for a player whose contract they don't want.
Teams have the list of players on waivers, but MLB does not release it. The most likely players on it are ones who have contracts that their team would love to take off the books, AKA, the Philadelphia Phillies. In truth, most MLB players will be placed on waivers.
If two different teams put in claims on a player, the claim goes to the team with the lowest winning percentage in the same league. Sometimes, a team will claim a player just to block another team from acquiring them. The Phillies, with their winning percentage nice and low, would have priority over most other teams making a claim, but have no reason to do so, being (unofficially) out of contention. Teams are horrified of bulky contracts right now anyway, so this practice will be uncommon this August.
Players like Utley and Rollins with 10-5 rights, or Byrd and Burnett with a no-trade clause, are still in control of whether or not they go anywhere. A team can claim Chase Utley as much as they want, but if he wants to finish his career in Philly for some reason, he's still going to do so.
Once August 31 rolls around, the waiver process resets and begins again, but players acquired in September can be barred from postseason rosters, which is why of the two months, August is the more frantic.
The Phillies have plenty of middling players who could fill a hole for a team in need, trying to stabilize for a run. They also have Cole Hamels and Chase Utley, who are great baseball players. These guys are all likely to be claimed, and the Phillies, with an apparent newfound grasp on the future, may make a deal or two (but not for Hamels or Utley). Somebody like Cliff Lee, with his contract and current injured status, or the aforementioned Howard, will not hear a peep.