This feature could mean a lot for all types of apps meaning it could possibly hide and show views and forms based on the logged in user. At the moment it's almost impossible without some javascript and workarounds.
It could simply mean that users approaching lists for all users can have different content forms, views etc based on the connections that user has with the content.
This would work in countless types of apps because of users having active content for each record and history connected to that record from a public listing.
Here's some examples
Recruitment - Can hide an application form because the user has already applied.
Appointment booking - hide the form and shows the appoint already booked
Sales - Can show your order if you're viewing the same product that's been ordered
...not only could you hide but you could exchange forms, reports, e-commerce etc and direct users in a much more dynamic way.