Tim Cook speaking during Verizon's iPhone 4 launch event in New York
Apple CEO Tim Cook is expected to announce the iPhone 5 later today. Reuters

Apple's hosting a news conference at its headquarters later Tuesday, where the company is expected to end 15 months of speculation and anticipation with the unveiling of its next smartphone -- the iPhone 5.

The previous iPhone 4, unveiled more than a year ago, continued the legacy of Apple's phones before it and carried the flag as the most desirable consumer smartphone in existence. Industry observers believe the iPhone 5 won't bring any less cachet.

R.W. Baird analyst William Power told clients that Apple's new model, will continue to set the standard for smartphones, boasting new features that will define the direction of the industry for years to come.

Power believes what has become the Street consensus on features, notably that the new phone will probably look and feel a lot like the iPhone 4, but maybe will feature a thinner, faster, wider screened look, with voice-recognition technology for executing more sophisticated commands than the current device.

But consumers aren't only slated to win.

Investors are already banking on the continued success of the iPhone franchise. The previous iPhone 4 catapulted Apple to become the world's largest smartphone vendor for the first time in the second quarter -- pushing more than 20 million units in just three months.

But there's a huge pent-up demand for the iPhone 5, analysts believe, and the release announcement and rollout will lead to a huge boost for Apple shares.

In light of Apple's underperformance in the two weeks leading up at the iPhone event, said Ticonderoga Securitie's Brian White.

With the shares still trading at just 9.4 times the firm's 2012 pro forma earnings per share estimate, combined with the momentum in the company's portfolio, we would rather own Apple than any other tech company in the current environment, he said.

In premarket trading Tuesday, shares of Apple rose 55 cents, to $375.15.

Analysts expects long lines for the new phone since there was no traditional summer release, which has only served to push up demand as consumers were forced to wait until the fourth quarter. As a result, the new phone should sell more than the 1.7 million units that the iPhone 4 managed within the first three days of launching.

In comparison, Samsung's Galaxy S2 -- seen by many as the iPhone killer and Samsung's top selling phone -- sold five million units within 85 days, or roughly 170,000 over the same duration.

We expect iPhone 5/4S, iOS 5 and iCloud to affirm Apple's competitive advantages and differentiation, said RBC's Mike Abramsky.

Apple's news conference is slated for 10 a.m. PST at its headquarters in Cupertino, Calif.