Apple is set to begin manufacturing of the next-generation iPhone in late August, claims one analyst, with a release date sometime in late September. Morgan Stanley analyst Katy Huberty made the prediction in a research note following meetings in Taiwan, which were likely with some of the Cupertino company's suppliers.

The prediction lines up with those of other analysts and Apple watchers, most of which have targeted September as the time for the introduction of the new iPhone. Huberty wasn't explicit on what she expected the next-generation iPhone to be, although she did say two million units are expected to ship in the fourth quarter.

In addition to the new iPhone in September, Apple may be moving to diversify and expand its portfolio in 2012 with new models. Huberty said that the company itself is forecasting a significant jump in shipments, "on the back of new products and potentially lower price points."

Whether this means a cheap iPhone 4 like what Apple did with the 3GS, or a new smaller device altogether is unclear -- although rumors of an "iPhone nano" have persisted for a year or more now.

Another analyst, Deustche Bank's Chris Whitmore, actually believes the September launch would bring two phones: the higher-end standard iPhone, as well as a cheaper unlocked device that would be intended for prepay customers.