I use MC for movies, music and family photo collection. For photos, I am only beginning to get organized. I found tagging the files directly in Windows Explorer is a powerful tool, as these tags appear as keywords in MC. I have a view that lists all thumbs and where I can filter based on (multiples of) these keywords, e.g. "Summer holiday", and get summer holiday pictures from all years. You get the idea. For now I prefer tagging in the OS, as these tags also are useful directly in Win8.
One thing I really miss in MC is the simple ability to right-click a photo to either copy it to clipboard or "Save as...".