So SharePoint 2010 Service Pack 1 is available for Download.
The SharePoint team are also shipping a June 2011 CU with a bunch of fixes that didn’t get into SP1 and it’s “ strongly recommended to install the June 2011 Cumulative Update immediately after the installation of Service Pack 1.”
More detail over on the SharePoint blog: http://sharepoint.microsoft.com/blog/Pages/BlogPost.aspx?pID=984
Also included are a few FAQs.
So, what’s in SP1?: Check out Andrew Connell’s post about What’s New In Service Pack 1, this of course is additional to all the hot fixes and previous CUs that are bundled into the service pack.