Without any change on the chassis and features, most people won't really know if you are owning a new or new-new iPad! It is pretty much like the upgrade of a CPU in normal PC. It is not good to a gadget and I suppose people who already own an iPad will not buy another one so soon while those who don't have one now may also won't eagerly consider to buy one just because of the more powerful CPU. I don't think this hardware upgrade can help the sales of iPad much. The iPad mini however is another story!
I bought my "new iPad" (aka iPad 3rd generation) in March of this year, making me a proud owner of a now outdated device. I passed on the first two generations of iPad devices, and have enjoyed the Retina display of the "new iPad". So much of the press keeps repeating the fallacy of a 6 month product lifecycle, because it was actually a 7 month product lifecycle (March + 7 months = October). Having worked at Intel it came as no surprise to me that Apple would obsolete its own product, because "Only the paranoid survive", if you don't leapfrog your own products then the competition certainly will.