According to The Korea Economic Daily (a major publication in South Korea), Samsung will unveil the launch date of the Galaxy S8 on February 27, the day when MWC 2017 officially opens its gates.
Not long ago, we heard that Samsung would announce the S8 on March 29, and release it almost a month later, on April 21. Now, we just have to wait for MWC to start and see if these dates are accurate.
The Galaxy S8 is expected to bring a bevy of enhancements and new features. The latest rumors have it that Samsung will launch a regular, 5.8-inch Galaxy S8 alongside a 6.2-inch Galaxy S8+. The screens of both models should be curved at the edges and occupy most of the phones' front sides. Likely powered by Qualcomm's new Snapdragon 835 CPU, the Galaxy S8 series should be available to buy via all major US carriers, just like most of Samsung's previous Galaxy S flagships.
source: The Korea Economic Daily (translated)