The “cloud” is a retarded paradigm for home automation, and I would never have cloud-enabled spyware devices anywhere that I live. IPv6 will come sooner or later. This has a large enough address space to give every house in the world a few quintillion static IP addresses.
No need for a cloud server when your device can just connect directly to any device in your home via SSL or other encrypted link.
Why the fornication would I need to go through Google’s servers to talk to my thermostat if I can connect to it directly with my smartphone? (Some mechanism for initial discovery via being on the same WiFi network would be easy to implement, or a central server could act as a mediator rather than storing and transferring actual data.)
As far as your question about cameras, something like this plus a NAS drive would be easiest to set up…
