Difference between SQL Server 2005 & 2008

Can anyone give me some description about differences between SQL Server 2008 a开发者_StackOverflow社区nd SQL Server 2005?

Are there changes comes in update query or any new feature in 2008 version?

What's New In Sql Server 2008 - MSDN reference, comprehensive listing

What's New In Sql Server 2008 R2 - same, but for 2008 R2 version

What's New In Sql Server 2012 - same, but for 2012 version

Most important, in my opinion, are:

• MERGE
• Chained OUTPUT
• Ability to pass table variables into the stored procedures
• Native support for materialized path (hierarchyid)
• Filtered (partial) indexes