There will be people who love the new features coming out.  While I'm not really into the whole social networking thing at the moment, they are neat little features.  I just wish they are a little better.  There really isn't much to the Twitter app.  You just post your status and well, that's pretty much it.  With Facebook, I wish you could chat with your friends online (the IM thing) from your Xbox.  The Last.fm addition will be used by a lot of people I think.  Just search for something you like an away you go.  I just wish you could use last.fm outside the application it self.  All and all, they are nice but, Facebook and Twitter could have used a little more work but, they still get the job done.