You can install Unity on Arch[1], but you also need to install several libraries with many Ubuntu-specific patch[2], since Ubuntu loves to patch stuff downstream.
I'm also not sure if it will work flawlessly, as I haven't tested it. But, for example, Ubuntu ship with also a patched Mesa, that it's missing for that project and it's supposed to contain some Unity-specific patches.
There were some projects to include Unity in OpenSUSE and Fedora[3], but it seems a dead project now and it's not available for the latest versions of those distro (last version supported: OpenSUSE 12.2 and Fedora 17).
I'm also not sure if it will work flawlessly, as I haven't tested it. But, for example, Ubuntu ship with also a patched Mesa, that it's missing for that project and it's supposed to contain some Unity-specific patches.
There were some projects to include Unity in OpenSUSE and Fedora[3], but it seems a dead project now and it's not available for the latest versions of those distro (last version supported: OpenSUSE 12.2 and Fedora 17).
[1] https://wiki.archlinux.org/index.php/Unity
[2] https://github.com/chenxiaolong/Unity-for-Arch (See "order to compile/install")
[3] http://en.opensuse.org/openSUSE:GNOME_Ayatana