Hey Jack, I don't know for sure but I'd guess it would be coming out in the Phase 2(?) release that is due out the 1st Quarter of this year. From what I've heard, it has some very exciting improvements & new features.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .