Read about Gnome-Shell – Bleeding edge + installation too.

The GNOME Shell redefines user interactions with the GNOME desktop. In particular, it offers new paradigms for launching applications, accessing documents, and organizing open windows in GNOME. Later, it will introduce a new applets eco-system and offer new solutions for other desktop features, such as notifications and contacts management. The GNOME Shell is intended to replace functions handled by the GNOME Panel and by the window manager in previous versions of GNOME. The GNOME Shell has rich visual effects enabled by new graphical technologies.

To try it out, open terminal and write:

sudo conary update {clutter,gjs,gir-repository,gobject-introspection,mutter,gnome-shell}=foresight.rpath.org@fl:2-devel

These packages have no conflict with existing ones (unless you have installed older versions of them yourself), so don’t worry and just go ahead.

After it’s done, run this:

gnome-shell --replace

With this command, gnome-shell (and mutter) will take over your window manager (metacity) and gnome-panel. If you can’t see a working gnome-shell (it’s not working for me on several machines with old nvidia/intel/ati card, but runs smoothly on my laptop with nvidia 8400), pressing Ctrl-C should be able to kill the command (you should still be in the terminal window if you don’t take many actions).

If you want to use it as the default environment, do:

gconftool-2 --set /desktop/gnome/session/required_components/windowmanager gnome-shell --type string

Log out and in, done. That’s it, now you got a really cool desktop in Gnome.

Source: Taken text from http://wiki.foresightlinux.org/display/~jesse/Try+Out+GNOME+Shell