Microsoft launched a new preview site for SQL Server 2008 R2. You can sign up for notifications about the releases of CTP's.
From an administrative viewpoint, focus seems at tools to manage, utilize and consolidate instances and machines.
Towards usability (mainly business intelligence), enhancements to integrate with Office 2010 (mainly Excel and SharePoint) are featured. Also further integration with Virtual Earth is shown.
Finally there is mention about something called Master Data Services and the Stewardship Portal. In concept a very powerful way to create and maintain a data warehouse bus.