You would expect that Google will use Android@Home protocol in it's Android@Home demo , right?
Well it looks like Google got caught cheating. It looks like Google has actually used equipment from Synapse Wireless  and their protocol called Snap , and not their own, in-house developed Android@Home protocol.
Why did they do that? My guess is that they have limited developer resources who could code such a complicated protocol and wanted to do field survey how would press, other companies and general public react before they pored expensive development hours into questionably interesting product.
Nice try Google, but it is still cheating.
I would like to share comment from LinuxMCE  (most advanced smart home solution and it runs in Linux) forums by Darren:
"Interesting.... but Google would have to buy it and open it up a bit more for it to provide a real alternative.
From the Synapse website "Synapse Wireless Inc. provides patented hardware and software technology that helps tie together devices for remote monitoring and control."
So in terms of an application layer free of patents - not at the moment. But perhaps Google will but the company, open source the stack and donate the patents to one of the open consortium's.
We're still in for a bit of waiting it seems."
I really hope that either Google buys Synapse Wireless and releases it's patents to one of open consortium's or does so with their own (hopefully in development) Android@Home protocol.
 Android@Home demo at Google Keynote
 Google’s Android@Home – The plot thickens…
 Synapse Wireless
 Snap protocol