Facebook is currently testing a new feature called “Subscribe.” A source who supposedly has it enabled, tells All Facebook that “by subscribing you don’t miss any updates from people you subscribe to.” While on the face of it, this would seem to be a lot like the idea of “follow” it’s not clear from that wording if you actually already need to be friends with a person in order to follow them.
Here’s Facebook’s comment:
This feature is being tested with a small percent of users. It lets people subscribe to friends and pages to receive notifications whenever the person they’ve subscribed to updates their status or posts new content (photos, videos, links, or notes).
Facebook also confirmed that you need to be a friend of someone (or a fan of them) in order to get these notifications. These notifications go into the tab up top and also get sent as an email to you.