Smart meters will ultimately lead to time of day charging
The gap in the logic between 'smart meters save you costs' (which they don't as they only show energy usage rather than controlling it) and actually saving costs is a change in energy tariffs.
Most pay standard tariffs that apply regardless of the time of day.
Some may have Economy 7 meters for nighttime electricity usage, which may be cost effective when using electric storage heaters.
Having smart meters means being able to tell, by household, how much electricity is used at certain times of day and will lead to differential pricing for electricity during the day (e.g. pay less from 10am - 4pm, pay more from 7am - 10am and from 4pm - 10pm, pay least between 10pm and 7am).
Cost savings will only be available to those who then change their consumption profile.
Hold on to your cotton socks for a shake up in tariffs - only this will change behaviour - not looking at today's 'not so smart' meter which doesn't tell you very much.