Windows SharePoint Services 3.0 SP2 and Microsoft Office SharePoint Server SP2 include fixes and enhancements designed to improve performance, availability, and stability in your server farms. SP2 provides the groundwork for future major releases of SharePoint Products and Technologies. For more information, see Service Pack 2 Overview.
Internet Explorer 8 and Firefox support are updated. SP2 introduces a new Upgrade Checker, also known as stsadm operation preupgradecheck, to check if the server farm can be upgraded to Office SharePoint 2010. You will need to upgrade your current site to SP2 before updating to SharePoint 2010.
Read-only content database is supported in Service Pack 2. A new SQL defragmentation timer job is added to improve database health.
For a list of features for each Microsoft Office SharePoint Server, see Service Pack 2 for the 2007 Microsoft Office System due to ship April 28th. For a summary of the update, see Updates Resource Center for SharePoint Products and Technologies on TechNet. For a white paper describing the service pack, see About Service Pack 2 for SharePoint Product and Technologies.