Just released, the WSS and Office Server Core CU packages are now out:

Description of the Windows SharePoint Services 3.0 hotfix package (Sts.msp): December 16, 2008
http://support.microsoft.com/default.aspx?scid=kb;EN-US;959644

Description of the SharePoint Server 2007 hotfix package (Coreserver.msp): December 16, 2008
http://support.microsoft.com/default.aspx?scid=kb;EN-US;959637

One important fix included in the WSS package is the fix for the approval workflow issue, which I covered in a previous post:

You use the Approval workflow in a document library, and you select SharePoint groups as approvers. Some of your domain trusts are offline. In this scenario, when the workflow is initiated, it fails, and you may receive the following error message in the Unified Logging Service (ULS) log:

System.SystemException
The trust relationship between the primary domain and the trusted domain failed.