Implemented Let users "subscribe" to items/categories

Hi there,
I am using showcase for a while now and I am watching how my users use that feature. I noticed that it is a cool way to show something, it won't let you keep track if something changed and they see no reason to check things out again, so I thought about this to motivate my users to revisit the items: (also I still want to evolve showcase from a enhanced gallery to something like a simple project management system )
Let them be able to subscripe to specific items or categories, and even a user (which could be done with the xenforo internal following system, so in your personal timeline on the forum is a note that XY created/edited an item).
It would be great if that would inform people if somebody changed the description of an item or created a new one.

To subscribe to a category could be implemented via: http://xenforo.com/community/resources/bd-forum-watch.660/
Just an idea which could make your life easier if you decide to implement this.