At first blush, that sounds like an unthinkable concept. The smartphone is so deeply ingrained in our lives that “there's an app for that” has become a catch phrase for life itself. Moreover, the smartphone hasn't even seen its tenth birthday yet; how can it possibly be necessary that this device depart our lives? Despite the strangeness of the concept, and the numbers that seem to shout otherwise, there's still a lot of good reasoning behind the idea that the smartphone's days are numbered.

The numbers beg almost immediately to differ. In 2014 smartphones meant $380 billion in revenue, with over 1.2 billion devices sold. By 2018, that market will swell to $451 billion. Estimates suggest that there are eight billion smartphones set to hit the market by 2020 alone. So how in the world can the smartphone be on the brink of death?

The answer is one-word simple: growth. The last several years have reportedly seen growth rates in a steady decline, suggesting a market that has reached full maturity, a market where everyone already has one of the things in question and therefore is in less of a hurry to buy new. From there, the market will likely die off to some degree as the next big growth market emerges. Manufacturers' margins are slim, and much of the gains in the field are going to Apple with everyone else competing for second place.  There are even some comparisons between Apple right now and BlackBerry (News - Alert) at the height of its power, with the key difference that Apple is a bit more diversified.

So what's likely to take over for the smartphone? Some are already looking to wearable devices like Google Glass, which some believe simply came out too early to overcome the cultural issues associated with such devices. Some, like venture capitalist and CNBC commentator Ed Fernandez, note: “Our heads can't continue down-staring at our screens. Something must be done to fix this, and the basic technology to do it are already there.” We've seen augmented reality systems before, not just in Google (News - Alert) Glass but also in Microsoft's Hololens, the Magic Leap system and more. Throw in natural language processing interfaces, artificial intelligence technologies, and the connectivity of a smartwatch able to talk to a television or the like and the next system starts to take shape.

There's a lot of speculation going around, and a lot of possibility, too. Will our “next smartphone” use a current smartphone for its processor power? Will the devices contain processors alone? Considering what's at stake, though—the potential replacement of a market that generates a conservative $350 billion annually in revenue—that could mean something very big afoot. But will consumers be willing to make the jump that quickly? It largely depends on what's offered, and if what could be becomes what is, there may be many more willing to take the leap than expected.