According to the official Ubuntu development calendar, this week Ubuntu 17.04 version will be released or also known as Ubuntu Zesty Zapus. This version is the 26th version of Ubuntu, a version that will still have Unity 7 as its main desktop as well as the official Ubuntu Gnome flavor.
The new version will be released on April 13 as established by the calendar and among other new features, the version will have kernel 4.10, X.org 1.19 and MESA 17.0.3.
Unity 7 will be the default desktop for this version and will contain some new features, but these are limited to correcting bugs and stability problems found during the last months. On the other hand, Gnome, although it is not the default desktop, it will contain many new features, including the latest version of this desktop, Gnome 3.24.
Despite the announcement, Unity 8 is still in the official Ubuntu 17.04 repositories
The different programs that make up the Gnome desktop will also be within the Ubuntu 17.04 repositories but not in its latest version, that is, in version 3.24, but in previous versions, depending on the decision of the Ubuntu and Ubuntu Gnome team. A) Yes, Nautilus, Gnome's most famous file manager, will be in version 3.20.
According to last week's announcement, it will be next year, 2018 with the release of the next LTS version when Gnome will be the default desktop, meanwhile Unity 7 will be the default desktop. It also draws attention the incorporation of new versions of Unity 8, an unstable desktop that although it will not arrive on Ubuntu, it is still in the official repositories of the distribution.
Ubuntu 17.04 will be a stable and final release, but due to last week's announcement, this future release is still a development release, a version where we can see how advanced the synchrony and operation between Gnome-Shell and Ubuntu is.