Unity: Very Intrusive & A Nightmare To Maintain
Along with the discussion around a rolling-release version of Fedora Linux, having been discussed recently has been the possibility of providing Ubuntu's Unity desktop as an alternative desktop environment for Fedora. This is obviously a topic that gets some riled up.
The discussion about Unity desktop packages as a possibility for Fedora has basically died since there's no Fedora package maintainers interested in doing the legwork at this point and most importantly is that Unity doesn't take advantage of many of the upstream GNOME APIs. With incompatible API implementations for some packages, this makes working with Unity a pain if wishing to still fully support the GNOME 3.x desktop in a streamlined manner.
Nelson Marques jumped on the list having worked on the initial Unity support within the openSUSE project to provide a few words. In the email he basically explains that Unity isn't an option now for openSUSE and never really made it too far.
"Unity is not available for openSUSE" and Marques filled a request to just get rid of the openSUSE GNOME Ayatna repository completely. But here's the key part of the message he was trying to get across to the Fedora camp: "Unity will never become a part of openSUSE unless it uses upstream API. This was made very clear by Vincent Untz since the early days, which I totally subscribe; I think it's probably correct to say that either me or Vincent fully endorse what was said by [Jef Spaleta]."
In addition, what worked at one point in openSUSE was just the Unity 2D version, but not the proper Ubuntu Unity desktop with Compiz and the whole shebang. Running proper Unity in Fedora is also made more challenging by the Fedora plans to drop Compiz. [It's also been brought up in the forums that Gentoo is also doing away with Compiz.]
Nelson Marques ended his message to the Fedora developers with, "My personal stance is that the patch level from Unity is very intrusive and it's a nightmare to maintain. I wish the best of luck for Fedora in such achievement."