SBS 2008 includes the Update Services component to provide the administrator with a simple interface for managing software updates from the SBS Console. Those who are familiar with Update Services from SBS 2003 R2 will find that the SBS 2008 implementation is quite similar. It is essentially a wrapper for the native WSUS 3.0 interface meant to simplify the management of software updates for the network. By default all critical updates, security updates, and update definitions will be automatically approved for installation if at least one machine on the network requires it. Other updates are manually approved by the administrator as needed.

Full Article: SBS Blog