Implications of being post-PC
Those implications were:
Identity: a post-PC device needs to know its owner's identity since it can't rely on obtaining that information from a PC. At the moment all the devices are building their own identity platforms but eventually they'll start to take advantage of existing identity systems like Webfinger and PGP.
Personalisation: a post-PC device can be uniquely personalised because it's not predicated on the idea that it will be a shared device. The classic example is the experience when you buy a Kindle from Amazon. It will be preconfigured with your name and the books you've already bought. It's a small step from there to a future where the moment I bought a device in a shop it would automatically know that it belonged to me.
Cloud: post-PC devices tend to be heavily dependent on the cloud in order to store persistent state and to perform sophisticated processing. The definition of the cloud that this implies comes from Simon Meacham. He says that the cloud means treating the union of all those servers/networks/services as if they were one machine available to be used by everybody. In this vision the physical devices we own are merely portals to and caches for this metaphorical "one machine."
Mobility: if our data and services live in this cloud then all the devices I can log in to are equivalent. At this point the ability to take a device to the place I wish to use it (for instance the Kindle screen is supremely legible in bright sunlight unlike the screens of most mobile phones) and the fact a given device is ready-to-hand will trump all other considerations. Photographers have long had a saying "the best camera is the one you have with you" and the rest of the world will soon experience something similar.
Devices: new kinds of devices become possible, if not inevitable, in a post-PC future. Technology will migrate to the most convenient form and place in your life. That means computers, cameras and music players will start becoming features of watches, jewelry and clothing. That's partly because people actually like their watches, jewelry and clothing whilst they mostly tolerate their computers. The early examples of this are Nike+ and the increasing variety of smart watches. In fact several of the people attending OSJam were wearing the precursors of the smart watches of the future. Furthermore once people stop expecting technology to be delivered to them in a beige box it opens the doors to new innovators such as Arduino enthusiasts and the open source hardware community.
|From OSJam 19 - Post-PC: gadgets of the now|
Personal Area Networks: The logical culmination of this is the personal cloud or personal area network. This is not merely a network of devices that are physically close to one person. Instead it is a network of devices that are geographically distributed but which can connect to each other (via a variety of networks and protocols including the internet, wifi and bluetooth) and prove that they belong to the same person. The devices are tied together by the fact that they belong to a single person and therefore they can seamlessly share each other's functionality.
These are merely my guesses about what's likely to happen as a consequence of these post-PC devices. Ultimately Alan Kay is right: the only way to predict the future is to invent it.