Yeah, that's exactly the kind of schema with the kind of functionality I envisaged.
Some would have said to just get the controller to handle it and push out a bunch of messages to every sensor, but that seems like a lot of effort. As I am looking at mysensors as a means to implement my own complete home automation solution, the state of certain items (I like the examples given in your first post) no matter where your sensor happens to be is important to me. Security alerts seem like a good example, but the power to alert to anything information a sensor can provide is quite powerful, and I think would be a v.cool feature.
I can help in any way I can, but I'm not a coder (though am prepared to jump in and learn as much as is needed to get to the end result).