SharePoint 2010 Service Pack 1 was made available for download today (28 June 2011):
http://support.microsoft.com/kb/2460045
Specifically, these are the key areas of improvement in SP1:
- Improved support for Internet Explorer 9.
- Recycle bin: Lets you restore a site collection or a web that was deleted.
- Remote Backup Systems (RBS) and shallow copy can decrease downtime and increase efficiency by moving pointers to databases instead of moving databases.
- You can see which folders are taking up valuable space with the improved Storage Management feature in site settings.
- Support for Microsoft SQL Server 2011.
- A more robust Search Host Distribution service that improves error recovery and performance during the search crawl.
- Adds backup and restore functionality to recover deleted site collections and webs.