I think "lightbulb" is the modern incarnation of "toaster".
A more sensibly net-connected gadget is your fridge. It could be registered with the National Grid as a device that can be commanded "off" at a moment of critically high demand. A fridge will stay cold enough for at least half an hour without power. You'd get the electricity the fridge uses at a discount. At a future date it might also be able to deliver an inventory of its contents to your phone while you are in Tesco.
Or your central heating system, which you would command on with your mobile phone maybe half an hour before you arrive home, so home is warmed up. More efficient than having a timer set for your usual home time, that you forget to cancel on the evenings when you'll be home late.
But if light bulbs could predict their likely failure within the next fortnight, that could be useful. A sane implementation would be to alert your house-controller, which you'd have programmed to mail you or text you alerts if you are that way inclined, or just to quietly add a new lightbulb to next week's shopping-reminder list. (Just like printer alerts at work, if you think about it).