The October Cumulative Update was released on October 28th (please refer to this post: Announcing the release of the August Cumulative Update for Project and Project Server 2007 for more information on Cumulative Updates and the first one released last August).
Please read the following TechNet article for deployment guidance: Deploy cumulative updates (Project Server 2007)
Knowledge Base Articles and Downloads
Title
ID
KB URL
Download URL
Cumulative update packages for the 2007 Microsoft Office core suite applications and for 2007 Microsoft Office servers: October 28, 2008
958847
http://support.microsoft.com/kb/958847
Description of the Project 2007 hotfix package (Project.msp): October 28, 2008
958138
http://support.microsoft.com/kb/958138
http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=958138
Description of the Project Server 2007 hotfix package (Pjsrvapp.msp, Pjsrvwfe.msp): October 28, 2008
957696
http://support.microsoft.com/kb/957696
http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=957696
Description of the Windows SharePoint Services 3.0 hotfix package: October 28, 2008
957691
http://support.microsoft.com/kb/957691
(not published yet)
http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=957691
Description of the SharePoint Server 2007 hotfix package (Coreserver.msp): October 28, 2008
957693
http://support.microsoft.com/kb/957693
http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=957693
Christophe has posted the links to the October Cumulative Update for Project and Project Server 2007
Great job by our writers for this October Cumulative Update (not to mention the PM, Dev and Test involvement). 
The TechNet team has just published this key article Deploy cumulative updates (Project Server 2007)
The December Cumulative Update was released on December 16th (please refer to the email attached for