Re "Saving you money"
Another thing that nobody here has mentioned is that of a smart meter's ability to measure Reactive Power. On AC systems any non resistive load will have a Power Factor (leading or lagging) of less than unity (1.0), and the actual power drawn from the grid will be greater than that stated on the label. Virtually all modern switch mode PSU's (this includes all your "Energy Efficient" CFL & LED lamps) have little or no PF correction - the £15 plug in monitor I bought from Maplin shows this, and can typically be as low as 0.5. So your 11 watt bulb will draw 22 volt/amps. Now if your supplier decides, at some point in the future, to start charging you in Kvahr instead of Kwhr your bills will shoot up. I downloaded the UK smart meter spec, and this ability is confirmed to be part of it, along with the remote switch-off and parasitic draw. An episode of TV's "How It's Made" showed the assembly of a smart meter, and the first stage was the baseplate and isolating switch, so there's absolutely no doubt that this is possible. Also remember that the grand plan envisages "Smart Appliances" which will talk to your smart meter - this greatly extends the possibilities for suppliers to remotely control much of your consumption. Temporarily turning off fridges, freezers and things like aircon (unusual in the UK) are likely to be employed to reduce demand during other peaks.