I see a goal of smart metering to ensure the grid has visibility over demand. At the moment NatGrid rely on the frequency to determine how much to supply to meet demand, this is somewhat inefficient and can be problematic.
I don't see how that can possibly be true. Frequency is the only feasible way to manage the short-term (second-by-second) demand/supply balance, short of complete redesign of the whole system (and very limited alternatives even if you had a blank sheet). Smartmetering as currently implemented doesn't have any means to respond anywhere near that quickly. It does offer finer grain data to improve the accuracy of forecasting models, though these are quite good already and it's not clear how much benefit is there to be gained.
Control over demand is something that has to be coming soon particularly for EV charging, but it's not clear who is going to manage it. It might be driven by variable pricing and customer-owned equipment that responds to the dynamic price (probably from the smartmeter) to minimise cost; it might be driven by electricity suppliers offering cheaper tariffs if they have control of your charge time, or it might be third parties who offer the end user some money in exchange for control of your charging (the latter two possibilities based on the new remote-controlled chargepoints that the OLEV grant scheme is causing to get installed), or it might be controlled by car manufacturers via the comms links they typically already have.
It's not obvious which of those will win, nor how the tension will be managed between optimising charge times for lowest cost based on grid-level demand, vs managing supply capacity in the local networks. If everybody in the street needs only 1 hour of 7kW charging overnight, and electricity is cheapest from 2am-3am, who gets that slot and who gets moved to 4am-5am so that the fuse at the transformer doesn't blow? This is one reason for thinking that the price-signal-from-smartmeter model of demand management might not be the way forward, especially now that the ownership of the various assets has got spread out - the smartmeters are managed by the customer's supply company, which might be different for each person in the street.
This would have been much simpler if DNOs had been given responsibility for (smart-)metering, but unfortunately that ship sailed long ago.