PC Mag posted a news story on the delayed release of Windows Vista Service Pack 1

Nash updated the Vista team blog Monday to say that it "was an issue with the way the device drivers were reinstalled during the SP1 update process, not with the drivers themselves – these drivers worked on Windows Vista release to manufacturing (RTM) and they work on Windows Vista SP1. For new PCs with Windows Vista SP1 preinstalled, this is not an issue," he wrote.

Microsoft: SP1 Drivers Not Malfunctioning