Here's something to think about: If the Phillies make the playoffs, the games may be heard on not one, not two, but three radio stations. And possibly a fourth.
CBS's WPHT (1210) is the flagship. Clear Channel's WUBA (1480) broadcasts the games en español. It hasn't been publicized, but get this: Sports talker ESPN 950 also has the rights to postseason Phillies play, though it carries the ESPN network feed and not Harry Kalas, Larry Andersen and Scott Franzke.
A fourth station would be CBS's WIP (610). CBS has been simulcasting Eagles games on WYSP (94.1) and WIP, and there's no reason to believe that CBS would turn down the chance to sell playoff commercials on a second station. Of course, if a Phillies playoff or World Series game were to fall during an Eagles game, well ...
Let's not get ahead of ourselves, shall we.