Will it be thinner than a piece of cardboard and just as light? So blazing fast it downloads apps before you know you need them?

It's barely a month since the latest iPads hit store shelves, and the rumor mill is already running about the next iteration of Apple's top-selling gizmo, which created the tablet computer market in 2010.

Slimming the Size

The latest rumor isn't surprising: A Japanese blog, Macotakara, claims the next iPad will be smaller than its predecessor -- smaller by two millimeters to four millimeters (0.078 inch to 0.15 of an inch) and 17 millimeters thinner (0.669 of an inch). It's hard to imagine how Apple's engineers and manufacturing partner Foxconn can keep slimming the design that way. Will it one day be as thin as cardboard? Perhaps, since that's why they're paid the big bucks. The Japanese blog post, which was picked up and translated by 9to5Mac in the U.S., said the newest iPad could be in testing at the end of this month.

The report, citing unnamed sources, also says Apple is moving its production schedule up to compete with Google's Nexus and Microsoft's Surface tablet refreshes, with the new iPad fifth-generation model due as soon as March. That's after the iPad 3, iPad mini and iPad 4 this year.

But the iPad 4 was not a substantial improvement over the iPad 3 -- which added a Retina display, faster processor, better camera and LTE-speed data as an improvement over the iPad 2. The current iPad has only a slightly faster processor -- 1.3 gigahertz compared with 1 gigahertz -- and a 1.2-megapixel front camera compared to the puny 0.3 megapixel version on the predecessor. You're not likely to demand a refund and rush for an exchange for that upgrade if you had the iPad 3. (The new Lightning connector, though supposedly allowing faster data transfer, annoyed many people because they had to shell out for adapters.)

So what's left for the iPad 5? There's only so thin they can make the thing, though cameras, display and processors can always be subject to improvement.

Michael Gartenberg, a technology analyst at Gartner Research, sees no reason Apple should worry about its top-selling devices losing momentum because they are not original enough.

"With almost every iteration of every Apple product since the first iPod, there has always been the comment of "What can Apple do next?" Gartenberg mused to us.

Forward They Go

"Apple has in the past found ways to continue to drive their product line forward in ways that capture the hearts and minds of consumers. The iPod of 2001 looks nothing like the iPod Touch of 2012, and yet continues to be a best-selling device."

As for the competition, Gartenberg said, "At the moment, those folks have the pressure to compete with Apple, not the other way around."

Some financial analysts, however, have lowered projections for the iPad and iPhone for next year based on reported supply purchases. Those projections may be based on the fact that so many people already own a tablet or smartphone and therefore aren't likely to run out and upgrade in the near future.

But one prediction we can make with complete confidence is that rumors and speculation about the next iPad and next iPhone will continue to circulate, as they always do, until Apple makes their formal debut.