We had the idea, about a year ago, to have trending lists for different npub categories (1-100 followers, 100-500, and so on).

nostr:nprofile1qqsykh4lg3nkfcesv3x5zc5jf2r2w0z3wvycewcqmv9xjzcfwqr2prspzamhxue69uhhyetvv9ujumn0wd68ytnzv9hxgtckzl8h7 is also working on manual labeling of npubs, so that we can have dynamically-updated category lists.

And the topical relays would be interesting, to focus on.