That sets a refresh schedule quicker than rival Apple's annual iPhone release.

The Galaxy line is a huge moneymaker for Samsung, contributing to its $8.3 billion in profit in the fourth quarter of 2012, though its unclear how the Galaxy S III is stacking up against Apple's iPhone 5 (the S III outsold the iPhone 4S). Apple shipped more iPhones during the fourth quarter than Samsung shipped Galaxy S IIIs. Samsung sold 40 million S IIs, but Apple's figures lump the three available iPhone models together.

The Next Bigger Thing?

How Samsung will again position the device as "the next big thing," as its marketing proclaims, to overtake the iPhone 5 is sure to be an object of great speculation and interest in coming weeks. Two devices are somewhat evenly matched with high speed, long-term evolution data speed, lightning-fast processors and state-of-the art cameras, but the iPhone is slightly lighter and thinner and has the advantage in available apps , as well as Apple's brand appeal. As Samsung's TV spots will point out, the S III has an edge in near-field communication ability for mobile payments and quick transferring of data, photos or media.

The Galaxy S III, like many Android -based phones, also accommodates a micro SD card for memory expansion of up to 64 gigabytes, something no iPhone model can do.

One advantage Samsung has is that it cranks out refreshes more quickly than Apple, potentially catching users of older iPhone models (or other devices) when their data contracts expire. The S III was released just eight months ago, in June.

The iPhone 4S was released in October 2011, and the iPhone 5 in September 2012. A new iPhone, possibly a cheaper model aimed at emerging markets, could be released at the end of this year.

Updated Features

"The upgrade cycle for Samsung appears to be a bit shorter than Apple, and more frequent with many more devices/tablets being introduced," said Kirk D. Parsons, a senior wireless industry analyst at J.D. Power and Associates.

"I'm not sure if the Galaxy IV will be any larger or thinner but I'm sure it will have some updated features to match that even may surpass what the iPhone includes."

And how could the company differentiate between the Galaxy S III and a Galaxy S IV?

"It's all speculation so far, but typically, [improvements] include a speedier processor, updated OS, possible richer display, etc.," Parsons told us.

Invitations sent out to the press Monday for Samsung's March event declare "Ready 4 the show. Come and meet the next Galaxy."

Meanwhile, Samsung released a new version of its Galaxy Note tablet , the 8.0, at the Mobile World Congress. The tablet could be a strong rival to Apple's 7.9-inch iPad mini.