Intel's convertible/hybrid Windows 8 concept.

(Credit: Intel)

Apple's CEO Tim Cook may have just thrown down the gauntlet to the Windows camp about nothing less than the future of portable computing.

Cook dismissed the idea of a hybrid MacBook-iPad device, during the company's second-quarter earnings conference call this afternoon. "You can converge a toaster and a refrigerator, but those things are probably not going be pleasing to the user," he said.

The toaster-refrigerator hyperbolic metaphor aside, it just so happens that Intel has begun to push the Windows 8 laptop-tablet hybrid concept. And it has even built a demo unit to prove the point (see photo above).

Intel's newly appointed PC chief, Kirk Skaugen, devoted a few minutes to the Ivy Bridge-based concept device in a keynote speech at an Intel conference in Beijing a couple of week ago.

So, Intel -- and no doubt its coterie of PC partners -- obviously think this is viable. And an important segment of the future Windows 8 market.

Intel's pitch has been consistent: in "consumption" mode, it's a tablet and in productivity mode it's a standard laptop. The "best of both worlds" argument.

Of course, it's good for Intel because those Windows 8 hybrids will use the latest high-performance Ivy Bridge processors -- or Atom "Clover Trail" silicon.

And there are plenty on the way. "There are a number of compelling of hybrid and convertible designs in the pipeline," a source familiar with future Intel-based Windows 8 devices told CNET.

(Credit: Apple)

But getting back to what Cook said. He went on to cite a Forrester Research study that forecasts 375 million tablets sold in 2016.