The CTP version of SQL Server 2008 Service Pack 1 (SP1) is now available. You can use these packages to upgrade any SQL Server 2008 edition.
These packages have been made available for general testing purposes only. Do not deploy the CTP software in production. Peer-to-peer support is available in the SQL Server 2008 forums.
Note: To obtain SQL Server 2008 Express SP1 CTP, Go Here.