The December Cumulative Update was released on December 16th. The next Cumulative Update (CU) is scheduled for the end of February, then Service Pack 2 will be available between February and April and it will include the February CU.
From this point forward each Cumulative Update will consist of a package that contains the latest of every hotfix patch that we have shipped. What this means is that if you build a new Project Server 2007 farm, you can apply the latest service pack (Service Pack 1), the latest WSS CU package and the latest SharePoint CU package and be completely up-to-date. The package includes the Infrastructure Update, there is no reason to install it separately (but you still need to install SP1).
Please refer to this TechNet article for deployment guidance: Deploy cumulative updates (Project Server 2007)
After applying the December CU, the file version should be: 12.0.6334.5000
Knowledge Base Articles and Downloads
|Title||ID||KB URL||Download URL|
|Description of the Project 2007 hotfix package (Project.msp): December 16, 2008||
|Description of the Project Server 2007 hotfix package (Pjsrvapp.msp, Pjsrvwfe.msp): December 16, 2008||
|Description of the Windows SharePoint Services 3.0 hotfix package (Sts.msp): December 16, 2008||
|Description of the SharePoint Server 2007 hotfix package (Coreserver.msp): December 16, 2008||
· Project Server TechCenter (TechNet)