There's no doubt in anyone's mind that the new iPad has a display that puts every other tablet to shame. But if you're interested in seeing what is perhaps the most vivid representation of just how much more advanced it is than the iPad 2's display, you'll need a microscope. Luckily, even if you don't have one, someone else has taken the trouble to do the comparison.
That someone is Lukas Mathias, a user interface designer by trade. He took his digital microscope and looked at the new iPad screen with a magnification of 80x. Then he did the same thing with the iPad 2. The difference between the two is what you see above. The new iPad's resolution is 2048 x 1536. It is officially the most pixel-dense tablet on the market today.
There are other devices with more refined pixels, like the iPhone 4S and the Xperia Play, but those have much smaller screen sizes. The larger the display, the more difficult it becomes, exponentially, to keep that kind of graphical fidelity intact. Of course, when the iPad 2 came out, many were already impressed with that display, so the question is how much further the technology can go.