Unlike other Apple rumors, such as the much anticipated and still unrealized Apple TV, few doubts remain that Apple is developing an iOS-based wristwatch.

In the past few days, the Wall Street Journal and the New York Times have both reported that Apple is exploring a computerized timepiece. And on Wednesday, Bloomberg weighed in to say that Apple "has a team of about 100 product designers working on a wristwatch-like device."

The timing appears to fit the pattern Apple followed when it introduced the iPod: The company has waited for a market to take shape and plans enter the fray with a product that's better designed and more useful, thanks to the strength of its underlying software platform, the inevitable contributions of third-party developers and an emerging cloud storage and e-commerce connection.

There's no doubt Apple could make an interesting iWatch. But what's less clear is whether the company can make a timepiece that's revolutionary. The iPhone matters because it brought mobile touch screens to the masses, put Internet-connected computers in everyone's pocket and revealed the popular appeal of a curated platform.

The iPod matters because it made the legitimate digital music market more convenient than downloading songs without paying artists or music sellers, and because it connected music management to personal computing.

The iPad matters because no other company had been able to make tablets work well, despite years of trying, and because it made computing-related activities much easier in environments where people aren't sitting at desks.

Apple surely hopes the iWatch will matter as much, but it's hard to see how that will happen. Combining a phone with a touch-screen computer changed the industry. Combining a watch with a touch-screen computer seems like more of the same. And indeed, as Bloomberg's report ominously notes, Apple's investors want more of the same. They're concerned that without another revolutionary device, Apple will not be able to sustain its high profit margins in the face of competition from Google, Samsung, and others.

But revolutionary products are not simply something that can be produced on-demand, as if one were producing a follow-up season of the hit show "iPhone." The tech industry worships its innovators, but even icons like Steve Jobs didn't simply reimagine entire industries at will. For every revolution, there are several failed uprisings, like Apple's Ping or Google's Wave. Revolutions depend on luck and timing as well as a determination to innovate in the face of naysaying.

Can Apple make the "wearable" aspect of computing matter in a way that can't be matched by strapping an iPhone or iPod nano to one's wrist? Is time-telling a function that can be enhanced with apps on a tiny screen or is the watch aspect of the iWatch irrelevant to the potential of having a subset of iPhone functions crammed into a tiny screen? Perhaps it's all a scheme to limit Google's power -- you're not going to be doing a lot of text-based searches on a device with a tiny screen.

Pictured above is how designer San Francisco-based designer Yrving Torrealba imagined an Apple watch. Time will tell whether Apple can do better. Dig into our slideshow to see iWatch's smartwatch rivals, past and present.