Rumors suggest that the Apple iPad 3 might have a higher screen resolution.
A so called retina display might give the iPad 3 screen resolutions quite a boost and allow resolutions of up to.
The iOS 5 SDK for the iPad contains images that are twice the size than normal. The resolution of the images:.
Retina Display Demo
Also rumored, a retina display:
The iPhone 4 already uses a retina display that makes the text and overall appearance much smoother, no matter what the size of the text / object is. You can find out more about the retina display at apple.com: http://www.apple.com/iphone/features/retina-display.html