The problem is, this is just a "teaser" of what it really could be, and it's totally disconnected from all the other "social" apps. It doesn't connect you to opening an IM chat (which is realtime, and often a lot more useful), there's no easy way to make it really integrate into a forum / messageboard (which is more permanent, and searchable), or del.ico.us (which helps with organizing and tagging resources that are shared with others), or a hybrid short url / spidering / social tagging site like my ittyurl.net, or a blog post with comments, or email notification of something I am following
http://petesbloggerama.blogspot.com/2008/05/social-api-we-really-need.html