I've been absent lately due to some family (and other time-related_ issues.
Be that as it may, my mainstay is Lucid (Ubuntu 10.04.4LTS) until it goes EOL. I also use CentOS and Debian (for servers mainly), and as of late, Linux Mint. I believe Debian is going to Gnome 3 and I'm not sure about CentOS. Linux Mint's Cinnamon is a conceptual-fork off of MATE ( mate-desktop.org ) and it's its own DE (Desktop Environment) versus a Gnome 3 fork. I personally like Gnome 2 best and would like to see the same features available in Gnome 3, but that won't happen any time soon. Cinnamon can be installed on Fedora, Linux Mint, Ubuntu, and even Zorin. The Zorin team may want to fork Cinnamon, I don't know; but I do know that the DE in the FOSS world is a bloody mess right now. Fedora is even going to leave X behind in exchange for moving over to Wayland in Fedora 17 (so the rumor goes).
Compiz is dead (except for Ubuntu if you use Unity), so there's many changes in many distros right now, but it will settle down in a bit I'm sure.
Zorin may not have Canonical behind it or have the large community of Linux Mint, and while in some ways that is a bad thing, because Zorin is such a small community, devs can be big fish in a smaller pond and have a larger impact on the whole.
Stay tuned