I would very much like to know this, too. As much as I see the value of being able to ask wolfram alpha stuff, my first thought when I saw the Siri presentation was, if "Turn Airplane/Silent Mode (Wifi,3G,...) on/off!" works. That would add a lot of value to it, as that would make the phone really "hands free". Furthermore I would not have to remember the insane amount of dialogs one sometimes has to go through, just to reach a certain setting (which is probably why there are so many apps that do nothing but turn features/settings on and off).