By 1976 the portable calculator market was saturated with cheap low profit devices. It was the quick advance in miniaturization, packaging, and manufacturing that brought the price down yet still allowed more features to be added.
Today the smartphone is relatively expensive and made affordable with lock-in plans and/or proprietary content channels. This is exemplified by the Apple products like the iPhone. However, as in the calculator business, the hardware will be further miniaturized and componentized so that any manufacture or a few OEM will be able to have a sustainable business model to make them. The OS will become standard on some platform (Android?) as it is for PCs where Microsoft’s products are still predominant. When this happens smart devices will become a commodity.
The cheapification is starting now. For example, Nokia is bringing out very cheap phones for the masses.
Of course, there will be niche markets for high-end or specialized smartphones just as there are now for calculators (like those with financial functions). These will not be a big money maker.
Are there any new devices to take the place of smartphones and provide that profit margin again? I don’t think so. Many visions of mobile computing were made prior to the actual experience of an always-on network available wherever one travels. Geek rapture was and is in Ubiquitous Computing where every surface could become your own personal console, you don’t lug around some device and the associated power supply issues. With Virtualization technologies and high-speed wireless networks this is within reach, only the GUI breakthrough to make any surface interactive, a touch screen, is currently missing. Mobile projection devices, flexible membrane displays, and other technologies will make this happen.
Today’s techie sporting the iThis or iThat will be tomorrow’s dinosaur afraid to immerse their avataric selves into the telepresence of the social consciousness.