There is not even an iPad 2 here, but rumors about the iPad 3 already started about two weeks ago. Apple is supposed to change gears on the iPad release cycle and is going to unveil a new iPad 3 in September at the annual iPod event. Today AppleInsider reports that an analyst named Ming-Chi Kuo told them that the iPad 3 will have an Retina Display similar to the iPhone 4.
Kuo also through out there that Apple is considering a device that has a screen-size between the iPhone/iPod and the iPad. Whether that device is an large iPhone or small iPad is supposedly not settled.
A larger screen iPod touch could be put up against the upcoming Sony PSP 2, which has a 5-inch screen. Apple always says that 9.7-inch is the ideal size for a Tablet and anything smaller is not going to work.