Recently I have had few emails asking about how to get hands-on in SQL Server 2008. As of now still July 2008 CTP is available to download as per this OtherBlogPost. Further as usual I would suggest the SQL 2008 'newbie' to review the books online about Getting started with this latest version...
Whenever a CTP release is available it is best to refer to the documentation to know about t he features that are available in this CTP are documented. In this case ensure you have downloaded the Books Online from that CTP release and open the BOL then go to 'What's New ( component_name ) '...