Oil analysis is a fantastic tool in the right applications. It actually tells a hell of a lot about engine health. Depending on the contaminants, it can tell what parts are wearing eg Cr, Pb, Al, Cu, Fe, Si etc. Will tell you whether you have wear in rings, bearings, bores, journals, contamination from fuel, coolant, dust etc.
Having said that it's less useful on seldom driven cars - more for fleets of engines running 6000 hours a year. It's normally the trends that they look for, as this tells you more than the raw data.
Another good option is to cut open the filter and examine the wear particles under a microscope (shape, size etc.) You need to know what you're looking at though.