Apple could ship the fourth generation iPhone as early as July, a financial analyst wrote in a research note. The new iPhone could ship a month after its official announcement, which is expected June 7 at the Worldwide Developers Conference in San Francisco, said Doug Reid of Thomas Weisel Partners. It will succeed the iPhone 3GS, which was announced on June 8 last year and became available 11 days later.

The new phone will run Apple's iPhone 4.0 OS, which will enable true multitasking so that users can run multiple applications at the same time, Reid wrote. The iPhone already includes multitasking features, but it is limited to only certain applications like email. Other improvements could also include a front-facing camera and longer battery life, Reid wrote. The iPhone OS 4.0, which was announced in April, also includes ebook reading and file organisation capabilities.

There is "significant consumer enthusiasm" for the next generation of iPhones, Reid wrote. The iPhone is available in more than 90 countries today.

AT&T is the wireless service provider for the iPhone in the US, but The Wall Street Journal in March reported that Apple was making a CDMA (Code Division Multiple Access) version of the iPhone for Verizon. Reid, however, said that Apple might not announce additional wireless service providers for the iPhone in the US at the WWDC.

Apple has not officially commented on the next generation iPhone, although recent events point to an announcement soon. In April, the Gizmodo website published details of a purported next generation iPhone model that was thinner but slightly heavier than the iPhone 3GS. Gizmodo bought what its editors believe was an iPhone prototype for $5,000 after it was found at a bar not far from Apple headquarters. Gizmodo returned the phone to Apple. Documents in a criminal investigation regarding the phone that Gizmodo obtained refer to it as a "prototype iPhone 4G."

A Vietnamese website also disassembled an iPhone prototype and found it was powered by an Apple-developed A4 chip, which includes an Arm-based processor. The A4 chip points to the iPhone having stronger multimedia and video capabilities. An A4 variant is being used in the iPad, which allows users to view 720p high-definition video.

In another possible sign that a new smartphone is in the offing, prices of the iPhone 3GS have dropped over the past few weeks. Walmart is selling the iPhone 3GS with 16GB of storage for $97 with a two-year mobile-phone contract. The smartphone is priced at $199 on Apple's website.

Reid's research note wasn't the only one related to the forthcoming iPhone this week. The new iPhone coupled with the iPad could cannibalise sales of the iPod portable media player, said Brian Marshall, a financial analyst at Broadpoint AmTech, in a research report.

"The iPhone/iPad has successfully integrated the functionality of an iPod into a sleek smartphone/media player and has effectively rendered a significant portion of the iPod product family obsolete," Marshall wrote. Sales of the iPod have been steadily declining over the past few quarters, Marshall wrote.