The first update to SharePoint Server 2013 has been released. The release notes one known issue and resolves another:
Known Issue
You receive the following error message two times during the update installation process:
Microsoft SharePoint Foundation administration tool has stopped responding
This issue occurs after you put the update in the Updates folder on a SharePoint server so that the update is installed automatically. However, the installation process is not affected when this issue occurs. To continue the installation process, click the Close the program button in the error message dialog boxes. Currently, Microsoft does not have a fix for this error.
Issue that this update fixes
Assume that you migrate some activity types (for example, Ask Me About) from a SharePoint Server 2010 server to a SharePoint Server 2013 server. You enable the Activity Feed timer job to generate activity feed events when users update their profile properties. In this situation, the activity feed events are not successfully generated on the My Newsfeed page in SharePoint Server 2013.
Note: This issue only occurs on a default tenant that has on-premises deployments for SharePoint Server 2013.
Download the update here.
12/12/2012
SharePoint 2013