SQL Server 2008 R2 Service Pack 1(SP1) is now available for download. SQL Server 2008 R2 service packs are cumulative updates and upgrade all service levels of SQL Server 2008 R2 to SP1. This service pack contains the cumulative updates of SQL Server 2008 R2 cumulative update packages 1 thru 6. You can use these packages to upgrade any of the following SQL Server 2008 R2 editions:
Link – http://www.microsoft.com/download/en/details.aspx?id=26727