The reality of these 'online' features is that they will more often be used to market other products and as people are finding out, servers won't be active forever.
Really, from what I have seen on BD-Live, it is not worth worrying about. The only remotely interesting feature was some of the real-time online trivia challenges but in the end there is only so much trivia you can have about one movie title and questions are quickly repeated.
BD-Live is a failed attempt to make older titles 'up-to-date.' Studios would much rather a title you purchased two years ago have trailers for new product when you pop them back in your player. That is what BD-Lives primary goal was, but the current hardware and software implementation is just slow and clunky.
The only thing I have used BD-Live for in the last six months is to register my Sony BDs for sony rewards points. It is in excusable that is takes nearly five minutes from the time you click on the BD-Live link to get to the user interface. This is on a hardwired BD35 over a broadband connection.