The most awaited CTP of SQL Server 2008 (Formerly code name Katmai) has been released on 06/04/2007.

You can download it from http://connect.microsoft.com/sqlserver. You can also watch Ted Kummert talking about SQL Server 2008 here

Some of the key improvements in this CTP are:

§  Table Value Parameters

§  Star Join Query Optimizations

§  Change Data Capture (CDC)

§  MERGE  SQL Statement

§  Declarative Management Framework (DMF)

§  VSTA Support for the Script Task and Component

§  AS Dimension Design: Improved Supportability and Integration of Best Practices