http://www.microsoft.com/sql/ctp.mspx

SQL Server 2005 Service Pack 2 CTP (November 2006)

Today Microsoft is releasing a public Community Technology Preview of SQL Server 2005 Service Pack 2 (SP2). Applying this new customer collaboration model to service pack releases demonstrates our commitment to customer feedback and validation as an important aspect of a quality-focused development cycle. Also as part of this new model, we are introducing a separate release tree for any future SQL Server security fixes so that customers can take advantage of timely, targeted fixes that are streamlined for security specific updates.