Like the faceplate iResQ revealed in February, this faceplate is approximately 1/4 of an inch longer than the faceplate from the current iPhone 3GS, but SmartPhone Medic's video makes it much clearer where this extra 1/4 inch is coming from. The display dimensions on the "4G" LCD are exactly the same as those on the 3GS, and the upper portion of the faceplate, where the headphone jack, proximity and ambient light sensors, and top speaker are all housed, is almost exactly the same size. The bottom of the unit accounts for almost all of the extra space -- notably, this is where the current iPhone 3GS's primary antenna is housed, near the dock connector. It's widely expected that the next iPhone will have an 802.11n antenna, so perhaps this accounts for the need to lengthen the iPhone's antenna section.
This faceplate from SmartPhone Medic differs from the one iResQ showed off in one very important way. While the faceplate from iResQ had no obvious new holes in it, the SmartPhone Medic faceplate has a small hole next to the top speaker, in approximately the same location as the current iPhone's proximity and ambient light sensors. Since those sensors are perfectly capable of operating through the iPhone's display glass, as any possible indicator lights would be, the most plausible reason for this hole's existence is a new piece of hardware in the iPhone -- quite possibly a front-facing camera.
One other thing was made pretty clear in the video: something is different about the display itself. Read on to find out what else has changed.