The next generation iPhone 5,1 is once again being rumored to include a lengthened, 16:9 ratio, 4-inch screen as well as a smaller dock connector port, and a (partially) metallic back plate. According to iLounge:
What we’ve learned: the new iPhone will indeed be longer and thinner than the iPhone 4 and 4S. Approximate measurements are 125mm by 58.5mm by 7.4mm—a 10mm jump in height, nearly 2mm reduction in thickness, and virtually identical width. According to our source, Apple will make one major change to the rear casing, adding a metal panel to the central back of the new iPhone. This panel will be flat, not curved, and metal, not ceramic.
A The Verge reader, Tom Collins, first posited the 16:9, 4-inch screen possibility almost a month ago and Daring Fireball's John Gruber lent his support to the notion. If Apple goes with it, they could simply lengthen the iPhone, or they could also make changes to the bezel and Home button to better optimize it.
iMore first broke the news about a new, smaller dock connector a couple of months ago so it's good to see some additional support for the idea. It makes sense since space will be at a premium, especially with an LTE radio.
Rumors of a return to the metal backplate have been around for years, probably since the day after Apple dumped the original iPhone's casing for the plastic of the iPhone 3G. Having metal-on-glass, the inverse of Apple's current glass-on-metal aesthetic, looks a bit odd. But so did the iPhone 4 design when it first leaked. Likely radio transparency will dictate the final composition.
Gorilla Glass 2 has been speculated since Corning showed off their next generation material at CES 2012 earlier this year.
So, overall, iLounge backs up a lot of what we've already heard. But here's the caveat: Apple has had several different iPhone prototypes in the works at the same time in the past. Sometimes there are more ambitious and more conservative prototypes. It's the way Apple works. (There's an old cliche about 10 designs, 3 prototypes, 1 product.)
Last year, prior to the iPhone 4S launch, a lot of information leaked about a radical redesign for 2011 as well. So while we're starting to hear similar information from multiple sources, it's always important to remember that nothing about the new iPhone, or any new device, is certain until Apple holds it up on stage, likely this fall.