Now that iPhone 4S has come and launched, iPhone 5 (or whatever Apple ends up calling the next generation iPhone), concept designs are once again starting to pop up. This one comes from designer Antonio De Rosa, who created the above iPhone concept and has given it the title of iPhone SJ, as it is Steve Jobs inspired. He imagines it having an A6 processor, a 10 MP camera, and a polycarbonate body. I don't particularly feel that an A6 processor or a better camera are out of the question for the next iPhone.
I don't think polycarbonate would be a bad choice for the body as it's extremely lightweight. It would allow Apple to create an even larger device and subtract weight. I'm not sure I would want a larger screen as that has its disadvantages too. Overall, I think the design is great but I'm not sold on Apple making a larger screen that would inhibit one-handed use. You can visit ADR Studio's site for more images of his design.
Source: ADR Studio