All we realised when it was released, although this wasn't as important as when Ipad 2 was put on the market. For some people like me, there aren't many important changes between the New and the previous one. However, if any change was important, it was the famous retina display.
I couldn't have an Ipad 2 in one hand and try to compare the displays, so I can't speak about the improves on it. Moreover, I am sure, it would be very difficult to elaborate a verdict because both displays are really good.
But there is one thing with which I got surprised. The graphics processor of the new Ipad is amazing. Pictures look great thanks to the display, but the transition between menus is even better, it's real! You can put a piece of paper on a desk and move it with your fingers and that's what you feel when you browse menus, the reality.
I tried to load this blog in the Ipad browser and that's how it looked:
Yes, not a very good view, but it worked.
I also wanted to show you how is the menu transitions, so I captured this (I had no idea about what to do neither where to touch, but you can see the effects of the menus quite good):