I don't think it's a 'home automation system' (like many in this thread assume), but just a standard way for any device to be smarter and connected. There are already smart devices such as ovens, microwaves and washing machines which are connected and controllable with an app. What I think Apple is trying to do is just to push a standard way to do this, so it's easier for everyone involved. Makes sense.

For example, your oven publishes a simple API via BLE which the iControl software understands and translates into a nice remote control UI. From there, you can get/set the oven temperature, set timers etc. There's also a possibility that anyone could write an 'oven' app, which can then control any oven. That way, it's up to third-party software how smart or automated your home becomes.