There are never really that many leaks, considering more than 600 players are theoretically exposed. I think it's less a tight ship than the fact that the Phillies don't have any high-profile players for agents, front office people or writers like Rosenthal to yammer about. In past years it was guys like Lee (who was reportedly claimed that one season) and Utley. And the sources weren't necessarily the Phillies, could have been anyone from any team.
We knew Utley cleared waivers because the Phillies were negotiating with multiple teams. We assumed Roberto Hernandez didn't, and was traded to the team that claimed him, but I don't recall if that was ever actually reported.
Heyman reported yesterday that Francoeur cleared waivers, while the the Braves pulled back Jim Johnson when they couldn't make a deal. I wouldn't be surprised if Hellickson hasn't been exposed yet. The only way you could get a better offer for him in a single team market is if that team was more desperate, which is unlikely to be true just a week after the deadline. I still think there is a chance we'll hear about it once it happens (which is to say, once he is claimed and the Phillies pull him back). And obviously Bourjos is going to get his turn.