Something like that would have a far greater effect on the cost and efficiency of controlling an environment than a single expensive thermostat in one room.
That's what bugs me about these kinds of products. They never address the real problem. They are only there to find a niche that you can sell a gadget into with some pretext that may or may not exist, like the idea that thermostats are hard to program. OK then, try this one, it's cheaper:
http://www.smarthome.com/30429/Venstar-T5800-ColorTouch-Full...
The thermostat is not the problem. Homes (and buildings in general) are wasting energy because we are still approaching thermal management they way it was done 50 years ago. Here in the US it is not uncommon to cover the top of a commercial building with black tar (for waterproofing purposes). And then you wonder why it cost so much money to keep that building cool. These outdated ideas and methods need to change.
That's the problem.