Ahead of the iPad announcement on March 7, Aatma Studio has released their vision of an iPad 3 concept, with retina display and the use of 3D holographics and table projections.
The first extravagant conceptual design choice to immediately take note of is the use of an edge-to-edge display measured at 2560x1140 pixels (a.k.a 'retina'). With the complete surface being a screen, alluding to a larger display, the entire front panel works as the home button to the user. This, I can say with some confidence, unless Apple pull out a complete shocker, will probably not occur, even though this form of tech is physically possible.
Probably the most fascinatingly possible would be the use of the magnets along the side of the iPad, used traditionally for the smartcase, connecting two iPads together to form a conjoined display. Elegant in it's simplicity, and following Apple's core value of figuring out how a consumer would want to show off their new Apple product before they actually know themselves. A blend of airplay technology and some form of connectivity through the side-magnets (NFC?) could make for something of a pretty nifty party trick.
Finally, and most unlikely, is when the iPad enters the third dimension with hologram players in a football game, and the emergence of game controllers out of the sides via projected images on the desk. While this is pretty innovative, and unlocks a whole new set of scenarios for its use, implementations like this are physically impossible on such a large scale, and probably the furthest away in terms of Apple's R&D calendar.