But if you want to make use of Gnome Shell extensions, then you're out of luck. The universe repository doesn't yet have the extensions packaged nicely. The only way to get them right now is to make use of a PPA repository.
~$ sudo add-apt-repository ppa:ricotz/testing
~$ sudo apt-get update~$ sudo apt-get install gnome-shell gnome-shell-extensions
Tweaking the extensions
By default, only the alternative menu extension is enabled. To enable other extensions you'll want to first install gnome-tweak-tool.
~$ sudo apt-get install gnome-tweak-tool
Log out then log back in to have the new Gnome Shell loaded. You'll also be able to change extension settings through advanced settings (search for it in the dash).