Microsoft released the first service pack for SharePoint 2010 recently.
Some of the improvements in the SharePoint Server SP1 are listed below
1. Support for IE9
2. Better crawl performance for search
3. Improved storage management - lets you monitor the storage for the folders in your site collection
4. Recycle Bin which will retain the deleted site collections. Site collections deleted by mistake can easily be recovered using this feature.
5. Support for SQL Server 2011.