Apple’s under pressure to upgrade iPhone as potential customers defray purchasing current models in expectation of a 3G model of the device.

Analysts claim iPhone sales are cooling off as customers elect to wait for the iPhone that follows the current models. This is frightening investors, who, already concerned at what’s seen as a slowdown in iPod sales are also now concerned the company may fail to hit its ten million iPhone sale target for 2008.

As reported by Apple Insider, Banc of American analyst Scott Craig yesterday trimmed his stock price target on Apple from $180 to $160, citing slowing demand in expectation of a new model.

Craig thinks Apple will sell eight million iPhones in 2008, and describes the release of a 3G iPhone and further price cuts on the first iteration of the device as critical for success.

RBC Capital analyst Mike Abramsky believes the impact of the 3G iPhone has been underestimated. He anticipates the 3G model will offer new features such as voice or video capture, real-time GPS, streaming video and more.

Abramsky said: “Apple is likely to offer a faster processor in the devices, along with more onboard memory, which will also increase speed, downloading/uploading rates and browsing experience.”

The analyst lopped $25 from his target price, offering a revised $175 goal for the company stock.