With the release of Fedora 26 just around the corner, the team has finalized the standard wallpapers to be included in Fedora 26 Workstation.
Until now, Fedora included the GNOME set of wallpapers by default in the Fedora Workstation backgrounds chooser. You will no longer get the GNOME backgrounds by default (other than the Adwaita background) starting from Fedora 26.
However, if you still need these GNOME backgrounds, you can grab them from the repositories in the gnome-backgrounds-extras package. According to the Fedora team announcement, you will get both the new Fedora set, and the GNOME set, while installing Fedora 26.
So here is a preview of the standard Fedora 26 wallpapers. These new wallpapers look pretty amazing!
Fedora 26 is slated to be released on 11th July 2017.
In addition to the Fedora 26 Default Wallpaper and the GNOME 3.24 Adwaita background, Fedora Workstation now includes a new set of standard backgrounds.

Default Fedora 26 background

Fedora 26 Standard Wallpapers
You may find some of the new wallpapers look familiar, that’s because they were all previously Supplemental Wallpapers in previous releases. Check out the Supplemental Wallpapers for Fedora 26.