Sebastien Bacher, software engineer at Canonical, recently posted a message on the Ubuntu Desktop mailing list in which he proposes that Ubuntu stays on GTK/GNOME 3.8 for the next cycle (Ubuntu 14.04 LTS).

In his message, Sebastien states the following reasons for staying with GNOME 3.8 for another cycle:

we (Ubuntu Desktop) are currently mostly happy with what we have;

the focus for the Ubuntu Desktop team is likely to continue to be Ubuntu Touch/phone next cycle;

due to the previous factor, we are going to be limited in resources to do desktop work;

it's a LTS cycle, we should focus on bugs fixing if possible;

GTK 3.10 deprecates several options, it would be good to stay away from those controversies for the LTS (see this as an example of what is going to happen once we deprecate those options);

it seems like the next RedHat enterprise edition is going to be based on GNOME 3.8, if that's the case it would make sense for us to focus on ;

bringing quality to the same version/share the maintenance work a bit.

For stability, this make sense since Ubuntu 14.04 is going to be a long term release and updating to GNOME 3.10 or 13.12 will likely introduce many bugs that can't be fixed in time because the Ubuntu developers are focusing on Ubuntu Touch/phone, but it also means that Ubuntu 14.04 will lag two releases behind GNOME which will affect Ubuntu GNOME, Ubuntu users who are contributing to GNOME as well as some non-core GNOME applications that require the latest GNOME technologies.





Sebastien Bacher's message is just a suggestion / invitation to discussion and not a final decision, but considering that there's not enough man power (because of the Ubuntu Touch focus) to fix everything in time for the Ubuntu 14.04 LTS release, it doesn't seem like there's an actual choice.