While there hasn't been much clamor for a first service pack for Office 2007, Microsoft certainly turned one out promptly. Released today, the update brings with it the following improvements, according to a Microsoft press release:
-- Full compatibility for SharePoint and other server products with Windows Server 2008.
-- Support for AJAX, "enabling developers to create custom Web Parts for their customers."
-- Manageability enhancements "to consolidate or repartition site collections across SharePoint content databases."
-- Performance enhancements, particularly with large files.
-- Improvements in performance and stability for Project 2007 and Project Server 2007.
-- Incremental security enhancements.
The full run-down of what's in SP1 is here (Word doc).