Hi!

Happy to help

Since iPad 3 has not yet been formally announced/released, I can't really give any concrete details as to what new and/or improved features it may have.

The biggest differences between iPad 1 and 2 are the iPad 2:

-Is thinner/lighter
-Has two cameras (front facing for FaceTime, and a rear camera)
-Slightly longer battery life (just slightly... you may not even notice the difference)
-The display glass is stronger than iPad 1, so shattering is less likely (although you should definitely get a case the same day you buy an iPad)

The iPad 2 also has a slightly faster processor than iPad 1.

Among rumored improvements to iPad 3 are --

An improved quality of the display (not bigger or smaller, just better quality -- one of the best quality displays possible on the market today) -- very probable

A faster processor will be used, probably a quad-core Apple 6 processor. -- very probable

Potentially, a flash will be added to the rear camera -- neutral probability

4G LTE speeds are also possible, -- somewhat probable

The official announcement should be on March 7th, when the next launch event is planned, but could be sooner.

Hope that helps. Thanks!