Based on inside sources, The Korea Times has reported that Samsung will be supplying their PLS (Plane to Line Switching) display to Apple which will be used in the making of. Right now, Apple is using the IPS (In-Plane Switching) display which are bought from several other companies amongst which there is LG too. The PLS LCD displays were unveiled by Samsung in November 2010. Seems like Apple is apparently impressed with the viewing angles of the PLS which are much more improved when compared to the present IPS displays in the iPad.
But, the earlier rumors have said that the next generation iPad was going to possess the same retinal display as its predecessor. This is because, using higher pixel levels would endanger the battery life considerably.
We will have to wait and see which rumors would become reality now.