The attached patch exposes the information in \u0005SummaryInformation and \u0005DocumentSummaryInformation as their HPSF value objects. I have tested this against 196 real-world Word Documents with great success, and it passes all the "ant clean-dist" unit tests. I didn't know what the Right Thing to Do(tm) was for the numerous exceptions that PropertySetFactory throws, so that's an Apache TODO.
Created attachment 17990 [details] Patch against trunk to expose SummaryInformation from HWPFDocument
I've created a new parent for HSLFSlideShow and HWPFDocument, POIDocument, which exposes the DocumentSummaryInformation and SummaryInformation (in the way that HSLFSlideShow did). If you grab the latest svn, you should be able to get hold of the Summary Information nice and easily.