As Apple readies its Sept. 12 event in San Francisco to unveil the new iPhone 5 industry analysts are now predicting that the device will be the bestselling smartphone of all time. Each new iPhone has outsold the previous version, and the iconic device has been the top-selling mobile phone since its 2007 debut.

The iPhone's five-year run as the top-selling phone is unprecedented. The last phone to have such a prolonged run at the top was the Motorola Razr, which outpaced its competitors for three straight years -- until the flip phone was blindsided by the much more powerful iPhone.

The industry's median prediction is that Apple will sell 45 million iPhone 5 units in the first three months after it hits store shelves. According to Macquarie Securities research, Apple is expected to ship 66 percent of the total smartphones sold for AT&T, Verizon, and Sprint after the iPhone 5 launch, up from 45 percent last year. And, for the first time ever, Yankee Group reports that more smartphone shoppers say they plan to buy an iPhone than an Android phone.

Some analysts think the iPhone could defy the odds and stay on top for a decade or more. There's precedent for that too -- from Apple, of course.

"I'd point to the iPod. Everyone said an iPod killer was coming, and it's still dominating the digital music market," said Carl Howe, an analyst at Yankee Group. "A fallacy we run into is 'X replaces Y,' but usually it's a situation where we have X and Y together. Radio did just fine after television arrived."

Not every research analyst agrees. "History suggests the odds are actually quite strong that a new form factor will inevitably emerge to disrupt the smartphone era," said Brent Iadarola, analyst at Frost & Sullivan. He cites pagers and feature phones as gadget categories that went extinct.

"Logic would dictate that at some point in time another company would come along and take over the mantle of technology leadership," said Jagdish Rebello, director of communications research at IHS iSuppli.

The iPhone 5 will leave a trail of winners and losers across the mobile technology landscape, says J.P. Morgan analyst Mark Moskwitz.

Apple is expected to challenge other handset makers head-on with the new phone's battery performance, larger screen size, and sleek form, Moskowitz said in an investors note released today. Whereas larger rival 4G LTE phones have been called "battery hogs" and "pocket hogs," the iPhone 5 is expected to sidestep such labels, thereby taking away market share from other phone makers.

An LTE-enabled iPhone will join a host of other 4G phones offering high data speeds on the go. As such, the PC industry could lose further ground to mobile phone vendors, hurting growth at such companies as Dell and HP.

Wireless carriers in the U.S. will likely see a slew of upgrades to the new iPhone over the near term, according to Moskowitz, putting pressure on their profit margins. The iPhone 5 will also force carriers to ramp up their 4G rollouts as more customers jump from 3G phones.

LG Display provides the in-cell panels, while Samsung is responsible for the graphics memory. LG Innotek makes the camera module, and Semco the chip capacitors. On the downside, the debut of mapping and turn-by-turn navigation on the iPhone 5 could be a small negative for GPS vendors such as Garmin and TeleNav.

Finally, certain semiconductor suppliers will see growth as a result of the new iPhone, among them Analog Devices, Fairchild, and Broadcom. But Intel and AMD may be hurt by the continued cannibalization of PCs.

"We view a China Mobile partnership as the biggest potential sales catalyst in CY13 [calendar year 2013] and any clue that iPhone 5 includes a chip compatible with CM's TD [time division LTE] network is a positive, in our view," Morgan Stanley analyst Katy Huberty said.

Eyeing the features that could pop up in the new phone, Huberty cites 4G LTE support, a larger and better display, an improved processor and more memory, a new form factor, 3D maps and navigation, a new dock connector, and new SIM card technology.

Phones built around Google's Android platform collectively outsell the iPhone, but that market is fragmented across many different manufactures and models. Nothing on the horizon looks likely to usurp Apple's iPhone as the top-selling device. Only Samsung's Galaxy S III is remotely close, selling 20 million devices worldwide since May, according to Samsung.

The current chaos in the smartphone market makes it even harder for an Apple rival to gain new ground. Almost all of Apple's would-be challengers are either in the middle of a major transition -- Nokia, Motorola, and Research In Motion -- or stuck in a legal battle, like Samsung.

Apple's longtime Achilles heel, price, is becoming less and less of an issue. The iPhone is available through a growing number of lower-cost carriers, and older iPhones are likely to get a substantial price cut once the iPhone 5 is released. The still-popular iPhone 4 could even be offered for free with a new contract, if Apple keeps its current pricing model intact.

"There's a brightly lit path for Apple to continue to dominate," said Ramon Llamas, analyst at IDC.