I think it’s only a matter of time before someone exploits a wireless mesh network that controls and reads home utility meters to get free water and electricity.
Until then, there is a problem of range and coverage.
Greentech media reports that Trilliant ( a smart meter neighborhood networking startup) has bought SkyPilot for it’s long range, WiFi-based communications. Skypilot (with over 500 customers in 50 countries – utilities, wireless Internet service providers (WISPs), and municipal agencies – deployments exceeding 50,000 devices) will help Trilliant get to the next stage.
The greentech angle makes sense, as remote data collection/remote meter reading eliminates the need for meter reader to get into a car and drive around reading meters.  However, remote meter reading using powerline communications has been around for a long time – so I think that the positioning is more a product of politically correctness and current fashion than pure innovation.
A more significant concern that I have is data security of wireless mesh networks – less secure and easier to exploit than powerline communications connectivity. I can visualize exploits of wireless mesh reading electrical meters to get free electricity and on the uplink to the network management center – attacking customer data bases resulting in a major data loss event.