I've just deployed a small change that can show some additional info for some link topics, depending on which domain they link to. So far, it's only enabled for YouTube and Twitter links, where it will show the channel name and tweet author respectively. A good place to see this in action is on a search for "trailers".
Currently, this info is only displayed in the topic listings, but we should be able to extend it elsewhere, as well as utilize it for searching/filtering (like "show me all topics that link to this YouTube channel").
What other sites/domains would be good to apply this to? Links to reddit aren't particularly common, but it could probably work well there by showing the source subreddit, something like "reddit: /r/blog". What other sites are "platform-like" where additional info about the source/author is important instead of just the domain?