Evan Blass tweeted an image of leaked branding for what could be the official logo, font, and colors of the Note7)">Galaxy S8+. This, in turn, also sort of confirms that the “Plus” name of a larger Galaxy S8 will be indicated with a “+” sign rather than “Plus” like the iPhone does.
Why wouldn’t it? After all, this is exactly how the Galaxy S6 edge+ was named. Calling it a "Galaxy S8 edge+" would also be redundant, as we are expecting both Galaxy S8 models to be dual-curved.
It’s quite likely that Samsung will no longer be offering a flat-screened counterpart of its newest flagship model (based on all leaks we've seen so far). The Galaxy S8 would be the second Samsung device to only be available in a dual-curved version (first, was the Note7).
The latest rumor points to a 5.7-inch screen size for the standard Galaxy S8 while the Samsung Galaxy S8+ could sport a larger 6.0-inch screen, both with dual-curved edges and really small bezels.