With its third iteration of the iPad media tablet, Apple plans to change its naming scheme and call it as iPad HD, not as iPad 3 as reported before. The new name will clearly emphasize the main improvement of the new iPad over the previously available model: dramatically better screen and moderate enhancements of performance.
The reports about iPad HD name came from various sources (1, 2) whereas third-party accessories suppliers like Griffin started to list products for the future iPad as for "iPad HD (3)". Since Apple tends to name its products in a simple way, it may easily mark its next media tablet as iPad HD (high-definition), just like it called second version of iPhone as iPhone 3G, not as iPhone 2, in a bid to emphasize support for 3G networks.
It is generally expected that Apple's next-gen iPad will have a 9.7" screen with 2048*1536 resolution, new system-on-chip with improved performance, optional 4G/LTE connectivity and other advantages over the current model.
According to some evidences, the iPad 3/iPad HD will be powered by Apple A5X system-on-chip with two ARM Cortex-A9 general-purpose cores, which is expected to be made using thinner process technology (28nm or 32nm) and have considerably improved PowerVR graphics sub-system to support 2048*1536 resolution with proper 3D graphics and high-definition video playback acceleration. Perhaps, Apple will also boost clock-speed of the A5X to improve responsiveness of the device.
Apple never comments on future devices and keeps everything secret ahead of product launches. It is expected that the third iPad will be released commercially in March, 2012.