From a message posted on Nov 3 to fedora mailing list by Adam Jackson the currently rawhide fedora will have a gnome-shell that no longer treat llvmpipe as an unsupported driver. This means you can run gnome-shell even on VirtualBox or any other VM or on a hardware without 3D support.
So the Gnome shell will be available to everyone What about Gnome fallback which was executed when 3D acceleration was not available. It will no longer be required.
Still the work on software rendering of Gnome shell is only 10% complete. (When i wrote this post).