But let's not think about that. One cool thing about clouds is that they are inherently interconnected. An iPhone-to-iPhone message is delivered more or less immediately through MobileMe. A message sent from my iPhone to my BlackBerry shoots from Apple's cloud to RIM's like lightning. iPhone and BlackBerry are full cloud peers with regard to e-mail. Similarly, if I add one of my ActiveSync-equipped, Exchange or Windows Live-connected Windows Mobile handsets to the recipient list of the message I send from my iPhone, the Windows Mobile handset will receive it in seconds rather than minutes. This isn't the result of a secret pact among Apple, RIM, and Microsoft (as if). It isn't cloud-to-cloud notification, although that will come when users demand it. Any push-capable client is a maximum of two cloud hops away from any other push-capable client. Mail servers that serve push clients deliver or relay inbound messages immediately rather than holding them in a queue that is processed at intervals.
As always happens when I set out to bring meaning to some fuzzy word, I end up concluding that whatever it is, if people need it, the technology or concept won't need a separate term to define it for long. Once you have clouds notifying clouds and private sub-clouds within public or enterprise clouds, there is no cloud, just peer-to-peer messaging. There are adaptable standards for rapid re-establishment of broken authenticated TCP connections, multi-channel streams to support interleaved notification during payload transfer (if we stay in a one socket per client model), and transparent reliable delivery. There are standards covering address book and calendar data representation and handset/desktop synchronization. All of the ingredients needed to make a services-rich global cloud are in the public domain. It's a matter of shedding the legacy baggage of clumsy session-oriented protocols and transports that were optimized for dial-up and time-metered networks. Clients would have to get smarter, but commercial users are already there. Cloud? What cloud?