I like GUIs, the User Interfaces which give to the user the power to control a computer, the software algorithms, the hardware and all the features it can provide.
Unfortunately GNOME, my preferred Desktop Environment on Linux, is continuously revolutionizing itself. A lot of fragmented alternatives like Unity, Cinnamon, Gnome Classic.. are popping out but I still see no benefit to break with the past and the new is anything special.
Tablets are not the ONLY future.
The mobile will be more important, any TV will look like a media center, but we'll continue to use a >11'' screen to do the important things!
The new GNOME mockups doesn't impress me much because there is a lot of space wasted and don't consider that the use case to put 2 windows side-by-side which is still important in the desktop computing.
There isn't a size which fit all for a GUI, but you can support better some common ones and use a CSS3-like technique like flexible columns with media-query.
Linux 3D graphic drivers sucks
Some drivers don't support all the features the hardware provides, some are proprietary, some are broken with the current Xorg ABI,..
GNOME 3 (shell) is unusable without nvidia-96 drivers which currenty don't support the latest Xorg. Considering many GNU/Linux users run it on old or cheap hardware.. it is a very unhappy move. Reinventing again the wheel is annoying and it demotivates a lot developers and users because it breaks the current stable status for an uncertain one.
The future is the Web
The main reason to break the current status now is the Web, and I mean a very simple concept: deep separation between User Data, Application Data and Applications.
GNOME3 has a nice experiment about it, but the data provider should be the web.
An external data provider hosting or a self hosted one, where to store, publish and backup your data and access to them independently if you use a desktop, a tablet or a smartphone computer.
An ARM Linux home server will help a lot to share the data across the family members, the rest of the world without lose the data control or be obliged to trust external web services.