There are too many integration points with Office 2010 and SharePoint 2010 to list in a single blog post, but there's one in particular that I'd like to highlight today: dragging and dropping files when uploading multiple documents.
We're all used to the Office 2007 way of uploading multiple documents... You have to select documents from a Windows Explorer like GUI.
But now with Office 2010, there's an improved screen that is much easier and more intuitive to use:
Of course, you have to have Office 2010 installed to use it. :-)