The GNOME team is working on a new project, Gnome OS, which is a Fedora based Linux distribution, with GNOME Shell as its default desktop environment.

Gnome tries to create a modern and stable new operating system. They have also included a new Application Center, based on PackageKit.
For now, Gnome has released a daily build GNOME OS, ready for tests on Virtualbox or VMWare.
How to test GnomeOS On Virtualbox or VMWare:
To test the new GnomeOS, download the daily build from here, and convert the image to a Virtualbox machine, with qemu:
Install Qemu Tools on Ubuntu / Linux Mint / Debian:
$ sudo apt-get install qemu-utils
Install Qemu on Fedora:
$ sudo yum install qemu
Download Gnome OS Image:
$ wget -c https://build.gnome.org/work/images/current/gnome-ostree-x86_64-runtime.qcow2
Convert Gnome OS image to an Virtualbox machine:
$ qemu-img gnome-ostree-x86_64-runtime.qcow2 -O vdi gnomeOSvbx.vdi
Now load your newly created gnomeOSvbx.vdi into VirtualBox and enjoy testing.
Alternatively, if you are a fan of VMWare Workstations, you can also convert the Gnome OS daily build qcow2 image to VMWare, with qemu:
$ qemu-img gnome-ostree-x86_64-runtime.qcow2 -O vmdk gnomeOSvmdk.vmdk
Now load your gnomeOSvmdk.vmdk into VMWare Workstations or VMWare Player and have fun.