Trust-rankings, yeah, and interoperability and implementation stats. You could even have an automated test attempt to write notes according to all existing models and see if they're properly displayed and post the results (accepts NIPs with eventIDs bunchofnumbers, otherbunchofnumbers, etc.)

And I like my idea of "like" notes, so that you can increase trust for objects (including other notes) and notify your followers of them.

Would be cool to have a list of those "like" notes, so that you could keep track of your favorite things.

I got the idea from the highlighter.