Not that we didn't hear rumors last year that there will be an iPad 3 with higher display resolution in the fall, which never materialized, but the sources say iPad 4 is necessitated by the fact that the first Windows 8 slates will be arriving then, which is much more believable.
The iPad 3 is said to come with QXGA (1,536x2,048 pixels) resolution, which we've heard numerous times, and longer battery life. We've also heard rumors that the high resolution required two LED light bars to be installed instead of one, which had made the slate slightly thicker than the iPad 2, but on the other hand it seems more room for a battery has been made, if the claim for a longer-lasting juicer is to be believed. The main goal here is to introduce the iPad 3 at the current iPad 2 price, which will be allegedly lowered to $399, to battle the influx of affordable Android and other tablets.
The iPad 4, on the other hand, is said to receive not only a more impressive hardware upgrade than the iPad 3 (quad-core A6 anyone?), but also to bank heavily on groundbreaking software side of things with some "integrated applications", whatever that means.
This one will have the first Windows 8 tablets to battle, both the ARM-based, and the ones with the new Clover Trail platform of Intel, which promises much better battery life than previous Intel mobile offerings, plus all the Windows programs you throw at it, of course, which is a major advantage. Both Acer and Lenovo are already said to out Clover Trail Windows 8 slates in Q3, so competition will be heating up in the tablet space this year, much to our delight.