Late last year, Facebook rolled out its group badges, little images and notes that appear alongside group member names within the comments section of group posts.

The idea is to encourage engagement - if you see that someone is, say, a 'visual storyteller', maybe you'll be inclined to check out their other posts in the group, while having your own 'Rising Star' badge might encourage you to be more active, adding a sense of belonging to that community.
And the initiative is obviously producing results, because in addition to the above group badges, Facebook has been slowly adding badges into Page interactions also, and expanding the signifiers available in order to highlight more prolific and engaged Page fans.

As you can see here, there are now 'Anniversary follower' and 'Milestone follower' badges for Page interactions, along with another 'Follower' icon, highlighting who's who within your post comment streams.

It's also possible for a user to have two badges simultaneously, which is now displayed with a '+1' notifier.

The additions expand the options for badges beyond groups alone, and provide new ways to Page admins to better understand their Facebook fans.
With these new Page badges, admins might be prompted to reach out to, say, anniversary followers and thank them for their engagement, or establish a new form of celebration, maybe even a giveaway, for those who reach certain milestones.
And Facebook's Page-specific badges could also, eventually, serve additional purpose. Back in June, Facebook launched a new Page post targeting option for Top Fans, giving admins a more specific way to connect with their most devoted audience members.

The option is only available for Facebook Pages with more than 10k followers (more info here), but it provides another way to boost engagement and reach, by focusing on specific, interested users, as opposed to sharing with everyone.
The expanded badge options could facilitate the same - maybe, for larger Pages, there could be ways to use these different audience segments for targeting, posting specific updates for long-term fans.
Facebook hasn't made any further announcements on this element as yet, but it's interesting to see the various Page badges popping up, and considering what other functionalities they could facilitate.