Well that was disappointing.
I installed the MS OpenXML SDK this morning (from http://www.microsoft.com/downloads/details.aspx?FamilyId=AD0B72FB-4A1D-4C52-BDB5-7DD7E816D046&displaylang=en) after reading about it in Woody's Office Watch. I was hoping it would have classes to let you generate Office documents on a server without having Office itself installed (been bitten by this before). Unfortunately, it doesn't. Or at least not that I can see from looking at the Class Reference in the Help.
BTW Microsoft, what's with shipping the help file as a CHM? I thought all DevDiv products now shipped with MSDN-style help (don't know the technical name for that one). The helpfile is also slightly unpolished - all the 'How Do I' topics are suffixed with '... using the OpenXML API' - isn't that slightly obvious in the OpenXML API Help!