At last the wait is over. SQL Server 2008 has finally RTMed on the 6th of August, 2008.
Evaluation editions of SQL Server 2008 are available for download from the MSDN and TechNet sites. Technet subscribers can download SQL Server 2008 from here, while MSDN subscribers can download it from here.
SQL Server 2008 is available in 7 editions including the new Web edition. Go ahead and try it out now. Microsoft has also included SQL Server 2008 in their August 2008 price list, which means it could be purchased right away as well.
For information on SQL Server 2008 editions and components see this.

Gogula G. Aryalingam (MVP - SQL Server)