MS Office 2010 Service Pack 1 Beta will be available at the end of 2010
At the moment invitations are being sent out to select beta testers who must already be using Office 2010 or SharePoint 2010. Those receiving the invitations are also required to fill out a survey for consideration in the beta tester selection process.
From the article: “Later this calendar year we will begin an invitation-only beta testing of the Service Pack 1 for Office 2010 and SharePoint 2010.”
Microsoft does not specify when exactly it plans to allow testers access to Office 2010 SP1 Beta and SharePoint 2010 SP1 Beta.