MS SQL Server 2008 R2 has been released, although it is the second release of SQL Server 2008, there are 10 major updates, I was most interested in StreamInsight, see the SQL Server 2008 R2 StreamInsight characteristics of interest . For development and small Web sites, SQL Server 2008 R2 Express is a better choice, not only because it was free, but now a single database size limit has been increased to 10G than 4G limit before lifting a large, concrete can refer to SQL Server 2008 R2 Express Database Size Limit Increased to 10GB.Can the http://www.microsoft.com/sqlserver/2008/en/us/R2Downloads.aspx SQL Server 2008 R2 Express to the left of the page to download.
SQL Server 2008 R2 Express Download
Microsoft SQL Server2008 R2 Express with Advanced Services
Microsoft SQL Server 2008 R2 Express with Management Tools
Microsoft SQL Server 2008 R2 Express with Management Studio Express
Also recommend everyone to download SQL Server 2008 R2 Update for Developers Training Kit (April 2010 Update) , learn the new features of MS SQL Server 2008 R2.