Samsung is today expected to unveil its latest Galaxy smartphone later today at a launch shrouded in secrecy.
The electronics giant is said to be anticipating sales of its new handsets to be as high as 10 million per month, but it has kept tight-lipped about the design of the mystery product, which has been at the centre of much hype in the run-up to its launch.
A teaser picture was published online on Tuesday showing only a shadowed image of the top of a dark handset.
Samsung Mobile US posted the shot on Twitter writing: "The countdown for #TheNextBigThing has begun. Who's ready for the Global Unpacked Event on March 14?"
Pictures of what was claimed to be the new S4 were released earlier by a Chinese forum, but observers have questioned the legitimacy of the photographs which show a device with a larger screen than the previous model.
While Samsung has refused to give anything away in terms of what customers can expect from their mystery offering, experts believe the highly-anticipated S4 handset could turn the mobile phone market on its head.
"If the rumours are to be believed the launch of Samsung's Galaxy S4 has the ability to disrupt the mobile market," said Greg Isbister, CEO of mobile advertising firm BlisMedia. "It would be great to see further progress made by Samsung on connecting its devices.
"The brand has a huge footprint in our lives; from washing machines and fridges in the kitchen to TVs in the living room, to phones in our pockets. It is already starting to join the dots by using mobile as the connecting device... This is hopefully a stepping point to more connectivity."
Among its predicted features are a 5in screen, wireless charging capability and a 13-megapixel camera, which would be able to take 360 degree pictures.
Some rumours suggest the device – dubbed Samsung's next big challenge to Apple – could include new eye-tracking technology that follows the user's gaze, automatically scrolling through pages as they are read to reveal more text.
Stuart Miles, founder of technology and gadget site Pocket-lint, predicted the S4 would be a big handset but suggested users could be "turned off" by a 5in screen.
"It will be interesting to see what they can do to make users want to upgrade," he added. "Samsung will probably have lots of people crying from the rooftops and saying they love it but I don't think it will become a mainstream device."
The phone is expected to be unveiled in New York and can be watched online at www.youtube.com/SamsungMobile