We've released the final version of the code snippets I told you about back in June. These are the same snippets, updated with the final schemas and namespaces that we used in the shipping version of 2007 Office System. There are 40 scenarios that enable you to write code in VB.NET and C# to access and edit Open XML files without the Office client applications.
You will want to uninstall the Beta snippets before installing these. They are licensed for you to reuse in your own applications however you see fit.