According to BGR -- which has a good track record with Apple rumors -- the next-generation iPhone, dubbed iPhone 5, won't be a minor hardware refresh as many have speculated and reported until today. According to the website, in fact, a source close to Apple's operations has confirmed the new iPhone will bring major changes especially in case design, which BGR calls a "radical" change. No other details have been posted on the alleged iPhone 5 specifications, though it needs to be mentioned that, among rumors of minor hardware updates and spec bumps, This is my next reported months ago the iPhone 5 would be a major update with a completely new design and a "tear drop" case / screen. The same report also detailed how Apple could implement a thinner design and an update Home button, capable of doubling as "gesture area".
BGR also claims an iPhone 5 announcement could come in August, with a release a few weeks later, although it's not clear how this would play out with Apple's usual music event in the first week of September:
According to our source, Apple may hold an event in the beginning or middle of August to announce the new iPhone, with availability to follow in the last week of August. We’re not sure if that means the iPod event will be moved up slightly, or if this will be an iPhone-specific event.
Speculation is running wild at this point as to whether the iPhone 5 will be similar to the iPhone 4 and only feature a faster processor (likely A5) and better cameras, or be a major change from the existing iPhone hardware with a bigger screen, different Home button, and perhaps NFC capabilities. Several rumors in the past claimed Apple would announce and release a new iPhone in September, shifting its usual release cycle from summer to the fall. As for recent rumors, whilst many publications reported the iPhone 5 (or "iPhone 4S" due to the rumored nature of minor update) wouldn't be a significant upgrade spec-wise, others claimed a curved glass screen and GSM/CDMA dual-mode could be part of Apple's announcements. Other noteworthy reports from the past months also indicated the "iPhone 4S" would go into mass production in August (thus backing up BGR's theory of a late August release) and that Apple was testing an A5-powered iPhone 4 prototype running on T-Mobile network.
Last week, it was reported the iPhone 5 reached the final testing stage, for a September 2011 launch.
Update: Aside from BGR's speculation, it's worth considering that Apple might want to ship the new iPhone model with iOS 5 already pre-installed, rather than forcing users to manually update to iOS 5 when it comes out a few weeks later, likely in September. In fact, Apple confirmed that iOS 5 is coming out "this Fall" after a beta period for developers this Summer. As several bloggers and tech pundits were already claiming months ago iOS 5 would come out in September, that might be the reason why many believe the iPhone 5 is set for a Fall release too, shortly after iOS 5 comes out. For example, when Apple released the iPhone 4 on June 24 last year, the device was running iOS 4 out of the box -- the OS was publicly released on June 21.