Windows SharePoint Services are now, collectively, called SharePoint Foundation. This makes sense, since a number of products (Dynamics, Project Server, Commerce Server, etc.) use these services. Microsoft Office SharePoint Server is now simply called the SharePoint Server. Hopefully, this will be easier to explain that the difference between WSS and MOSS.
While you're at it, try to call InfoPath > Design mode the InfoPath Designer (as opposed to the InfoPath Editor). Oh, and don't call anything Groove, either.