Office SharePoint Server 2007 SP1 is a much anticipated release in that it contains several key fixes and patches that affected many implementations.  However, installing SP1 requires careful planning, testing (regression and functional) as well as considerations and a deep understanding of farm topology.  Here is a great article on planning and implementing SP1 for SharePoint 2007:

http://technet2.microsoft.com/Office/en-us/library/f484f5f2-35bb-4d70-bf56-dd1c4c287c721033.mspx?mfr=true

 

A couple of key points that jump out at administrators right away might be:

  1. For Office SharePoint Server 2007, you have to install WSS 3.0 SP1 first and then SP1 for MOSS
  2. The update can be applied through Windows Update only if you have a standalone installation.  All other farm configurations will be required to have the updates installed on them manually by downloading the bits from the download center
  3. The Products and Services Configuration Wizard must be run following the service pack's application to the farm members
  4. Downtime will be required for the entire farm, so the application of SP1 should be scheduled for a time when it is the least disruptive to the majority of users
  5. There is no going back - Once SP1 is installed, it cannot be removed, so back up your servers (image backups, MOSS Backups, database backups, etc.)
  6. The content databases must be free from orphaned objects (See the above article for the KB link and details)
  7. Consideration for BDC enabled parent and child farms should be addressed (again, according to the article above)

The general advice is to take it slow, have planning meetings and implementation steps well documented and agreed upon by SharePoint, Windows and Infrastructure administrators.  Developers/Testers should be regression and unit test their code against the SP1 build of SharePoint and sign of on whether or not everything is working before SP1 gets implemented in production.  Many folks may be excited to get the SP into their environment, but it does require planning and testing for optimum implementation.