If the source of this report is to be believed, the standard version of the Samsung Galaxy S7 will come with a 5.2-inch display, but Samsung is also said to launch a 5.8-inch version of the Galaxy S7. Although this seems like a long stretch, bear in mind that Samsung's current-gen smartphone line-up includes two smartphones that are almost identical in terms of design and specs, with the only differentiating factor being the display size. We're obviously talking about the Samsung Galaxy S6 edge and the Samsung Galaxy S6 edge+.
The report also notes that the Galaxy S7 will come with a 4K display, but the source does not mention if this will be the resolution of the 5.8-inch display, or for the 5.2-inch version as well. The Samsung Galaxy S6 already comes with an amazingly sharp 5.1-inch display with a resolution of 1440 by 2560 pixels (QHD) at a PPI of 577, and going any further than QHD at 5.2 inches across the diagonal might be considered a bit of overkill. Note that the Sony Xperia Z5 Premium, the world's first smartphone with a 4K display comes with a 5.5-inch panel running a 4K resolution at 808 PPI.
Allegedly, the Galaxy S7 will come with 4GB of RAM, which would mean that Samsung's newfound capabilities of fitting 6GB of RAM inside a smartphone will be postponed until the Galaxy Note 6 rears its head.