Apple and Microsoft are going in that direction with their "cloud" networking stuff. We'll see how this pans out, but I think politics and greed will keep things segregated to a degree.
Everyone is really going towards "cloud" technology these days. Basically any online application can be considered a "cloud" application even if it wasnt called that a few years ago (webmail is a big one most people dont consider). A couple years ago when SaaS was new and exciting i kind of doubted that everything would be moved online and we wouldnt have installed software anymore... Now? I can kind of see it, with google docs and microsoft office live, salesforce, success factors etc... These were products which even 5 years ago companies would spend millions of dollars developing or implementing and require pretty beefy machines and back end systems to manage (CRM systems before salesforce were generally attrocious). It does help that i work for a SaaS company and I really get a first hand look at what kind of neat stuff can be done in SaaS though. With HTML 5, we can (and do) offer a product thats as rich as any ipad application, which on the surface doesnt sound impressive until you think of the state of "cloud" applications even 2 years ago. In another 2-5 years, what will be accomplishable in a web browser will be incredible, i think.
So yeah, as long as a computing device has a browser and some memory to store application state and data (16 gigs of RAM would probably do it for the foreseeable future), interconnected devices like we see in that commercial would be, and even are today, viable. Save your state on your phone, pick it up again on your table top, save again, back to your phone. It might not be as seemless between manufacturers as they show in the commercial, but we are pretty close as it is. And consumers would be more likely to buy an LG countertop, refrigerator, phone and TV (for example) if it meant you could do things like this, so interconnectivity between manufacturers kind of becomes a moot point, even less so if your state is saved to a server and not even the local device. Your next device can just download the state to its memory and resume, completely agnostic to operating system, device manufacturer and web browser, as long as HTML standards are followed (and every major browser is busting their ***** to ensure HTML 5 compatibility right now).
As for the power concern? We already generate and use power far more economically and efficiently than we did even 30 years ago. Power would be the least of my concerns for the future. We are no where near the limits of what we can generate or how efficiently we can operate electronics from what i can tell. Hell, even 15 years ago if you walked into a datacenter it was a giant buzzing, noisy, extremely hot environment. Its really incomparable to a modern rack of blade servers, both in terms of computer power available and energy efficiency.
