There is a lot of low hanging fruit that Fedora could provide over the upstream Gnome Shell
I disagree. The people who are working on gnome-shell and the desktop spin on Fedora are the same people who are working on gnome-shell and the GNOME desktop upstream. gnome-shell as it is represents our best effort to provide a polished, functional desktop that works for everybody. Now, everybody is not the same, and people have different needs and different tastes, which is reason why gnome-shell provides an extension mechanism. But it is meant for users to customize their desktop, not for distributors to differentiate themselves from upstream GNOME. For F16, we established the policy of 'no extensions on the desktop spin', and have consequently removed the ibus extension and the installer extension. If there are things truly amiss with gnome-shell in a way that goes beyond personal preference or special needs, then it needs to be addressed upstream in gnome-shell itself, not by distributors picking and choosing a random set of extensions to pre-install.
As for existing extensions, we really don't want to see them packaged in distributions. Within the next few weeks, extensions.gnome.org will be launched and allow users easy extension installation and deinstallation directly from the browser without any package involvement.--mclasen 18:05, 14 November 2011 (UTC)