I've just noticed that I've reached two milestones in my collection.
I am finally under 20% unwatched (movies and TV). This is based on having ever seen the thing, so it isn't necessarily true for that disc, just the title in question.
I am finally over 20% Blu-ray (combos counted as Blu-ray).
Both events snuck up on me, mostly due to a recent cull (which funded a few Blu-ray purchases).