Service Pack 1 for SQL Server 2008 has been released and is available for download. The service pack offers very little in the way of features, but is instead comprised of a rollup of cumulative updates and bug fixes. There is a note on the download page that seems like it was put there to address the disappointment that may be felt by those looking for new features:
We remain committed to our plans to keep service packs contained, focusing on essential updates only, primarily a Roll-up of Cumulative Update 1 to 3, Quick Fix Engineering (QFE) updates, as well as fixes to issues reported through the SQL Server community.
Despite the lake of sexy new features there are enough bug fixes to make installing the service pack worthwhile. The release of the first service pack for a Microsoft product is often the point at which many quality sceptical users take up the technology, so maybe this release will bring an increase in the adoption of SQL Server 2008.