This Could be the iPad 3 Case

According to MICGadget, this is the case of the iPad 3. As you can see, it has a tapered design, like the iPhone 5 was supposed to have, and like the MacBook Air. The widest end is larger than the iPad 2, but seems to taper down to the same size. Due to the edges being more tapered, it will still appear to be thinner.

What could the increase in size be for? If the iPad 3 will have a retina display, it's going to need a bigger battery. Also, a faster processor and 4G chip would also require a larger battery. With all Apple's adding to the hardware, it's going to need a bigger battery to support those upgrades. Until battery technology is improved, a compromise will have to be made, a larger battery means equivalent or better battery life, even with upgraded internals.

Seeing the case makes the iPad 3 seem all that more real. This looks like it really could be the next iPad case. Current rumors are pointing to the reveal on March 7th.
via 9to5Mac