iMore reported that the iPad 3 will be announced on March 7, and Jim Dalrymple, one of the most reliable sources about Apple Rumors, has confirmed the date. It also claims that the three most important new features of the iPad 3 will be a Quad-Core A6, 4G LTE from AT&T and Verizon, and a Retina Display. Tech n' Cars goes into detail on each one:
Quad-Core A5X: Of the three rumors listed by iMore, this one is the only one we aren't quite sure of. When the report came out, it called the iPad's new processor an A5X, but an image circulating around the web (to the right) shows an "A5X" processor inside the iPad, with a date code "1146", meaning it was produced in the 46th week of 2011, which corresponds, to November 14-20. This is about when production on the iPad 3 began. The picture made us at least 80% sure of this feature. Remember when everyone was going crazy about the iPad 2's new ultra-fast dual core processor? Well, I have no idea what people will be thinking when four cores go in the processor of this thing...
4G LTE: LTE, which stands for Long Term Evolution, is a new type of network that is significantly faster than 3G. This has been rumored for a long time, and Wall Street Journal recently confirmed the rumors. The iPad 3 will also be equipped with 3G or Edge so that when 4G isn't available, you can still "fallback to a slower network technology." We don't know if you'll be able to get one iPad that can run on either AT&T's network or Verizon's network or if you'll only be able to access one on an iPad.
Retina Display: Many people were disappointed when we were so sure that the iPad 2 would have a retina display last year, yet it didn't. We were so sure because even Apple was planning for a retina display, but they didn't have enough equipment. Well, Apple won't fail you again, because this time we're certain about a 2048x1536 retina display, because MacRumors confirmed the rumor by examining an iPad 3 display under a microscope.