I think an @ feature would be cool.
I would definitely agree with this as I honestly feel there is a big "popularity contest" aspect on the site already which would be even more pronounced with upvote/downvotes. I have said for awhile that good posts don't get likes, popular posts get likes, and sometimes there is a difference.
Why I care? That is a question I can't answer. I shouldn't care because it shouldn't matter to me at all but I guess I have some inferiority deal that makes me take notice of stuff like that.