iPhone 4
Apple's iPhone 4 is the most popular smartphone in the U.S. REUTERS

Entering a new month, here is another round of iPhone rumors.

The next-generation iPhone is now said to debut in October, instead of the much-rumored September launch.

John Paczkowski of All Things D, in its latest report about iPhone 5 release date, said "So those rumors claiming the iPhone 5 will debut in late September? They're wrong."

"Sources with knowledge of the situation say reports claiming AT&T has blacked out employee vacations during the last two weeks of September in preparation for the retail debut of the next iPhone are misinformed," continues Paczkowski.

The source declined to offer a specific date, but said the hotly anticipated release of iPhone 5 is going to be October. Other sources claimed the launch will be later in the month, instead of earlier.

According to reports, Apple has planned to sell as many as 25 million iPhones by the end of 2011. Considering a recent report that claimed 35 percent of people planning to buy a smartphone will buy the iPhone 5, it seems that Apple's sales estimates regarding the next generation of iPhone are spot-on.

There were reports earlier that Apple's iPod event routinely held in September will give way this year to the iPhone 5 launch. This theory took its origins after Apple said conclusively that its iOS 5, the latest version of the mobile operating system, will be launched in the Fall. The logic was, if iOS appears in the Fall, could iPhone 5 be far behind?

"In the best case, the iPhone launches in the first weekend of September and iPhone sales until then decline only 15 percent quarter for quarter," Sanford Bernstein's Toni Sacconaghi said.

"The launch weekend could see three million iPhone sales (compared to 1.7 million last year, when the iPhone launched in five countries that accounted for a then estimated ~60 percent of iPhone sales), given the boost from Verizon this year, where we expect the iPhone to launch simultaneously.

"We expect the post-launch weekend run-rate to drop by half and then continue to drop until it stabilizes at 20 percent global smartphone share at the end of the quarter."

September may come and go without any new iPhone; we don't know. Whichever date it falls on, the release date of Apple's next-generation iPhone will be highly anticipated, given the worldwide attention to the new model.

"Now, just four years after the release of the original iPhone, Apple has become the world's largest smartphone vendor by volume with 18 percent market share," says Strategy Analytics analyst Alex Spektor. "Apple's growth remained strong as it expanded distribution worldwide, particularly in China and Asia."

Apple raked in two-thirds of the total industry profit and is set up for a good second half as some consumers who are on the fence get lured in by new unveilings, such as the expected next version of the iPhone: the iPhone 5, according to Morgan Keegan analyst Tavis McCourt.