After launching the Samsung Galaxy S III, which had a resounding sales success, the company has began to work on its successor, the Samsung S IV.
The only surprise with this successor is found on its release date, which would be a little earlier than expected, and that this smartphone would be launched at the Mobile World Congress, so that shipments could begin as early as in March of next year(2013) providing we survive the Mayan calendar, just nine months after the debut of the Galaxy S III. This would imply a very aggressive product cycle.
About the specifics not much is known for now. Some rumors say that will have a 5-inch screen and a quad-core Exynos processor.