Cinnamon, the GNOME2-like GNOME Shell fork is now available in a PPA so Ubuntu users can easily get updates without having to manually download the .deb files.
Besides Cinnamon itself, the PPA also provides Cinnamon Settings, a new GUI tool that lets you configure Cinnamon: enable/disable panel autohide, tweak the date on the panel, enable/disable overview icon or hot corner, enable/disable themes and extensions.
Using the latest Cinnamon via GIT, you can also move the panel to the top (this feature should be available in the next Cinnamon release) and tweak some other settings.
Here's a video I've recoded running the latest Cinnamon from GIT (so there are some extra features that aren't available in the PPA yet):
Install Cinnamon in Ubuntu via PPA
Update: the PPA in this post has been updated with a new one which lets you install the latest Cinnamon (1.3.1 at the time of this update). See this: Alternative Cinnamon PPA For Ubuntu 12.04 and 11.10 Users.
To install Cinnamon Desktop and Cinnamon Settings under Ubuntu 12.04, 12.10, 13.04 or 13.10 via PPA, use the commands below:
sudo add-apt-repository ppa:gwendal-lebihan-dev/cinnamon-stable sudo apt-get update sudo apt-get install cinnamon
Once installed, log out and select "Cinnamon" from the login screen session list.
There's also a new Cinnamon Themes repository available on GitHub, but package isn't yet available in the PPA. Until it's uploaded, you can use the commands below to install the 8 beautiful themes you've seen in our video:
sudo apt-get install git-core cd && git clone https://github.com/linuxmint/cinnamon-themes.git cd cinnamon-themes ./test
And speaking of Cinnamon, the latest GIT version uses Muffin, a new Mutter fork created by the same Clement Lefebvre, as its window manager. For now, there aren't too many differences between Mutter and Muffin, but it will be interesting to see where this goes.