Really, seriously? you would swop your iPad2 for then newer iPad3 simply for the screen?
Perhaps you should have grown up in the days of two channel monochrome TV as I did, 12" screen with a huge magnifier on the front. You just might appreciate the screen on your iPad2 then.
I grew up with an Apple // and a green mono screen....I'm a tad older than you maybe give me credit for
But yes, a better screen would be the thing that makes me move up, not maybe right now, that depends on pricing and residual value of my ipad 2, but eventually...I think the retina display on the iPhone is wonderful and that's what I'd most like to see on the iPad....