A recent report from the Japanese 'World Business Satellite (WBS)' via TV-Tokyo makes claims of an iPhone 5 release in June, according to Macotakara. Foxconn is apparently hiring 18,000 new employees to support the launch, said a recruiter.
In Japanese major business news "World Business Satellite (WBS)" via TV-Tokyo had a program of "Launching the Rising-Sun Display company", Foxconn answered the reason for 18,000 hireling, "This (large hireling) is for iPhone 5 which will be sold in June".
The next iPhone won't be called iPhone 5 because it isn't 5th gen iPhone. There's a very slim chance that it could be called iPhone 6 since it will be the 6th gen iPhone and since iOS 6 will be release around the same time.
However, I really think that Apple will drop the numeric designation and call it "The New iPhone", following how they called the 3rd gen iPad, "The New iPad".
Of course this is all just speculation.
Would make sense as it'd catch the current ip4 users at the end of their contracts for those who didn't switch. It'd also keep them from going to another smartphone solution.
I do think it'll be a little different looking. If they try to pack LTE into it like the iPad then it'll possibly end up a little thicker. Maybe give it that slight curve design to hide that so they can measure the thinnest part and say it's that thin (lame marketing ploy)
I also imagine Steve Jobs worked on that before he passed. People often forget they plan these years in advance with lots of design control hoops to jump through. The 5S is probably on the drawing board as well.
I highly doubt the iPhone 5 design will be more visually appealing than the iPhone 4S. Add to that LTE won't come to where I live (3rd world country South America, Bolivia) in at least a year or two, I will hold on to my 4S.
If, somehow, the design of the iPhone 5 looks better, I will be upgrading nonetheless