The basic goal at WWDC is to tuen Apple products viral. If you have an iPhone, your wife will want one, too, so you can sync calendars with her. If your friend has an iOS device, you want one, too, to share songs. If your family has an iOS device for shooting video, you want one, too, to view the videos. If your coworkers are chatting on iMessenger, you want it, too, so you can chat with them. If students are transferring via AirDrop, you will want one, too.
It is all nothing new, but it makes iOS more viral than ever, and will ultimately sell more iOS devices.