(This can't be a new feature I believe, but both blogoscoped search for youtube autoshare and google site:blogoscoped.com autoshare resulted in nothing.)

Here is an old article describing it: india-server.com/news/youtube- ...

Here is a pic (after hitting the what is autoshare the text under the link appeared)

i32.tinypic.com/v7edxy.png

that was added a while ago on Uploads