iPad 3 will reportedly launch early next year.
The Wall Street Journal (via Gizmodo) says the third iteration of the tablet will come with a high-res, 9.7 inch screen with a 2048x1536 display, a significant upgrade from the current model's 1024x768 resolution.

This is just a rumour at the moment, but it does line up with reports back in June that said both Samsung and LG were battling for the opportunity to produce a full HD screen for the iPad 3.
http://www.computerandvideogames.com/316250/ipad-3-release-date-early-2012/