CentOS 6.3 and above will preserve most of your Lucid experience, and has support for some years. I have CentOS installed on my desktop PC.

http://dl.dropbox.com/u/8403291/centos.html

You will need to do some fiddling with repositories, research yum-priorities plug in and the various additional repositories.

I have Ubuntu 12.04 with Unity on the laptop and find it quite useful on the smaller screen. Looking at the Gnome 3.6 development screen shots on the original article, I might hunt up a ppa and try it...

It might get you similar versions of various software but RedHat derived distros (like CentOS) and Debian derived distros (like Ubuntu) are very different indeed. Were it not for the common Linux kernel, you might have as well be recommending FreeBSD.

Those are two completely different roots:

https://upload.wikimedia.org/wikipedia/commons/8/8c/Gldt.svg

True, and one of my reasons for putting centos on the desktop was to educate myself about the differences under the hood. I'm aware of the Upstart/init difference, and apparmor/selinux difference. Any references you have to share would be most welcome.

I seem to find that from an end user/desktop user point of view, CentOS delivers much of what Lucid/Squeeze delivered except no banshee (mono libraries not installed). I therefore point out the existence of RHEL clones whenever Ubuntu folk express concern at the shift from Gnome 2 to Unity or Gnome Shell when upgrading from Lucid.

CentOS 6 uses Upstart.