A new rumor is popping up, just in time for consumers to go do their holiday tech shopping: one analyst believes Apple (AAPL) is working on a new, thinner iPad for 2011 that would work on all of the Big Four U.S. cellular carriers’ networks.

Brian Blair of equity analyst firm Wedge Partners, has checked the numbers for Apple and Qualcomm (QCOM), and thinks Apple is developing a “World iPad” that uses one of Qualcomm’s multimode CDMA-GSM chips, according to a report from All Things Digital. Blair’s analysis states that the chip would enable it to run on both CDMA and GSM networks around the world -- basically, an iPad that could handle any carrier. It would spell the end of the AT&T/Apple exclusivity agreement.

Apple is banking heavily, it seems, on iPad being a big hit this holiday season, and has sold something like 7.46 million units as of late September. It’s showing up in all kinds of new places -- Best Buy (BBY), Target (TGT), WalMart (WMT), Verizon (VZ) retailers, AT&T (T) retailers, Amazon.com (AMZN) and even more. But Blair believes production of the iPad is already being backed down at Apple in order to make way for the World iPad, and some expect deals such as the reported $399 iPads at some TJ Maxx stores (TJX) to pick up as Apple tries to reduce iPad inventory ahead of its next-generation rollout.

Blair also states the iPad will be made from one piece of metal in a new manufacturing process, similar to the MacBook unibody approach, and that it’ll include at least a front-facing camera. It’s possible even more improvements to make the iPad work more universally, like some kind of USB functionality, might show up in the design as well, as Apple prepares to go toe-to-toe with tablets from other companies, like Samsung’s (005930.KS) Galaxy Tab. Samsung’s tablet is slightly cheaper, smaller and thinner than the iPad, and appears to be the strongest contender against Apple’s dominant mobile computing device.

Questions still remain

A new carrier-neutral iPad raises some questions, even as it answers a few. Recent moves by Apple suggest it’s preparing to go beyond AT&T and open up its devices to other cellular carriers. We keep hearing about a CDMA iPhone in the works for Verizon, and last month Apple allowed Verizon to start selling iPads in its retail stores; but even so, the iPads could only connect to the Verizon network with the addition of Verizon’s MiFi portable Wi-Fi hotspot device. Carrier exclusivity for the iPad 3G remains with AT&T

So for one, the rumor begs the question of what effect rolling out a new neutral iPad will have on the apparently burgeoning Apple/Verizon relationship. It doesn’t seem like this was the scheme all along, because one would think Verizon customers purchasing iPads and MiFis wouldn’t be too happy if a new, better and less technology-intensive iPad became available only months after purchase.

There’s also the state of Apple and AT&T to consider, as even through all this speculation and retail maneuvering on Apple’s part, it hasn’t deviated from the AT&T-only agreement up to now. If change was coming, it feels like it would have made more sense to make it a little earlier this year, when Apple was slinging iPads onto the shelves of all kinds of different stores and even made it available in its somewhat limited capacity to Verizon.

Regardless, someone drops an Apple carrier rumor about once a full moon, so without more information, it’s a tough call to make. But one indicator might be the state of iPad inventories in retail stores, especially later this year. If it seems like stores have just enough, or fewer than one might expect, it might be a sign that a change is coming.