The long waited release of Enterprise Library 5 is available on the Codeplex site.
Although the current feature list looks not that different from previous versions, a massive refactoring is done on all the Application Blocks to work with Unity and
dropping the old ObjectBuilder library. Also the configuration tool is now implemented in WPF.
Another nice addition is the new programmatic configuration support via fluent interface which make writing configuration in code more intuitive. This is especially useful if you want to get rid of the massive amount of XML configuration and start introducing some Convention over Configuration.
You can download Enterprise Library 5 from here.