1) You do not have to like a page to add it to an interest list (so it will be interesting to watch if this has any impact on user behavior around liking pages - I don’t know if it has on Twitter where you have the same options to follow/list). Just use the little gear icon at the top of any page.
I wonder if Facebook is planning a “list” button similar to the current like button, or social plugins to feature your lists. That would be neat.
2) Only users can create interest lists right now, not pages (too bad - it would have been nice to be able to curate lists as pages. Maybe this will come somewhere down the line)
3) Right now I don’t see a way to extract data on how many people have listed you or your page. Hopefully this is coming in the future, especially if some people start listing instead of liking pages.
You do get a notification when someone subscribes to your list, and a little heads up when someone shares it, as seen in this screenshot.
4) Right now I don’t see where other people can access your public list. Creating a list did generate a post on my wall (so ostensibly also in my friends/subscribers’ newsfeed), but I don’t see a place to access all my public lists from my profile.
UPDATE: It’s under your subscriptions. Not the most intuitive, but it’s there.
5) Just like posts, you can set and change the privacy settings of your lists at any time. You can also choose what types of updates show up in your list feed (posts, photos, games, comments/likes, music/videos, others).
In the same menu where you change these settings, you can decide whether you will receive notifications of new items in your list (notifications being a little icon showing number of new items, like for the pages you manage - I don’t believe these show up as your personal notifications). This setting is global for all lists rather than differentiable list by list.
UPDATE: So far the notifications have not been working for me - may just be a bug that Facebook needs to iron out.
6) Apparently top posts from your lists will appear in your newsfeed. I haven’t seen that happen yet.
UPDATE: Now I have. Here’s how it looks when that happens.
7) If you go to facebook.com/addlist, you can search all public lists by name and subscribe to other lists (also accessible by clicking “add interests” in the left sidebar).
Your own lists and subscribed lists are differentiated by the color of the list icon (green = subscribed, blue = own).
8) Just like everything else in your sidebar, you can move a list up to the favorites section at the top by clicking on the little pencil icon.
I’m going to keep updating this as I discover new quirks to share - interest lists have only been available a few hours so far, so I’m sure there’ll be much more to find.