Had the story broken on Saturday, there would still have been time for the weekly newsmagazines to make a big deal of the breaking news if they wished; Saturday evening is pretty much the last moment for most of them to make changes to what gets printed and mailed, though even then, it has to be a big story to warrant it. And the major Sunday newspapers, like The New York Times, could have run front page stories.
This was a conscious decision. They didn't politely wait to allow the owner of the property to go to the local media at her convenience. It was a calculated move, and it has backfired for Cheney, as has the decision to keep him away from the press for two days.