One of the perennial criticisms leveled at the home automation world has been that it's obsessed with technology for technology's sake. I think that, for the most part, thats justified. Like audiophilia, it's long been a hobby for whose practitioners the pleasure is as much in the process as it is in the end result. So you end up with houses that are the technological equivalents of ships in bottles: fascinating experiments in what's possible, but not great examples of what's useful or usable to most people. Lately, the Wired Home blog has been tackling this, which I see as a good sign.
Although gimmicky (the solenoid key fob car starter, especially) and still more about the technology than the end results, there are glimmers of interesting ideas. I, for one, would like to have everything in the house that makes noise grow quiet when the phone rings.
I would think you could also have some useful safety features as well. Should I really have to run around looking for how to turn off my gas when there is an earthquake? How about doors that lock automatically at night or when everyone leaves(Of course,speaking as someone who has locked himself out of a hotel room, this would have to be very smart).