Change the "world"? Lot of interpretation there, but I assume you mean in the context of photographers.
Speaking as one who operates a small camera and printing store, this certainly is a game changer, much like the 5D Mark2 was. This puts much higher quality captures in the hands of a great many people. We have customers come in every day wanting a large image of a file that doesn't have enough resolution. Then they want to crop it. they can't afford a higher resolution camera. They accept what they get because that's their only option.
these cameras are flying out the door, as are the 5D Mark III's. we're a long way from filling our waiting list. In the case of 5D3's and some of the d800's this means a large amount of used cameras available to others that now have a better capture device. end result, thousands of photographers getting higher resolution capability.
Currently it is estimated that there are several hundred thousand "professional" shooters just in the US - these are shooters who take pictures for "money" and very often provide "professional" enlargements. (debating their "professional" standing is irrelevant, they exist, they shoot a lot, and collectively represent a pretty large part of the market now)
I also have a good share of customers who are avid amateurs that are very skilled and do very nice work that also print sizes larger than the file can really handle.
Bottom line, everyone eventually has an image they want printed and printed large. You can talk all you want about never printing larger than A3 but almost everyone eventually gets an image they would just love a 30x40 of. A great many of those images are well exposed, just not enough resolution. Some are not so good, and the lack of resolution makes them worse. Hundreds of thousands of better capture devices moving into the market in an affordable price range means many of those prints will look better, some substantially better.
While it is true the skill lies in the person and not the gear, when making large prints you can't make up for poor resolution.
And to be honest this is probably just the beginning. Within a year there is a strong possibility a 36mp camera will come along for under $2k, and then someone will go to 40 or 45 megapixel (also maybe within the next year) and suddenly a 24mp full frame equivalent device will show up for $1400 ... within a few years the great majority of shooters will suddenly have the potential of better prints.
(and then new technology will make prints obsolete, but then those devices may indeed be retina type displays of 240 or better ppi so the higher resolution cameras still offer something)
Now how 'significant' all of this is and whether it "changes the world" is certainly debatable and really doesn't have an answer since the concept is pretty subjective. It's certainly changing my world ...
fun to speculate ... can't wait to see what's next ...