Denny Breitenfeld, the CTO of NetBlender told Gizmodo:
It's a technology that is built into our professional Blu-Ray authoring tool that will allow studios, independent movie companies to enable BD Touch features. These features send data in two directions from the Disc to the Iphone and vice versa. Video, Audio, text, and player commands can be sent.
So right now it seems everyone likes the "remote control" idea. However the player can control the IPhone as well. One idea is to automatically pull up IMBD of the movie you are watching right on your Iphone or send the movie information a movie database on your phone. The ideas are only limited to what people want and will use.
We are releasing an SDK for the 100k Iphone developers out there so they can take advantage of BD Touch features to build applications that easily work with all kinds of titles.