GNOME team decides to drop fallback mode
The GNOME project's release team has announced that the developers have decided to drop the fallback mode functionality from the GNOME 3.8 release. The decision is not unexpected; discussions about deprecating fallback mode have been happening within the developer community for quite a while. GNOME 3's fallback mode is used on systems that can not provide hardware 3D rendering, which GNOME Shell requires as part of its design. Fallback mode provides a 2D desktop that is similar to the user interface of GNOME 2.
According to Matthias Clasen, who wrote the announcement email on behalf of the release team, the developers are hoping to organise deprecating fallback mode "so that it does not create more fallout than necessary." The developers have not said what they will do to make GNOME Shell work on machines that don't support hardware 3D graphics acceleration. One common approach to the problem is to use llvmpipe technology which uses the CPU instead of the GPU for 3D graphics. This would enable most systems to switch to software rendering and is a solution that is used, with some limitations, in the current Ubuntu 12.10 release.
For the transition to be successful, the developers will have to move rendering of the desktop background into GNOME Shell completely, which will most likely also cause the desktop rendering functionality to be removed from Nautilus. There are also plans to unify the error message that is displayed when GNOME cannot be started for hardware compatibility reasons with the general "blue screen of death"-style error the desktop environment displays on critical system-level exceptions.
The developers say they will be publishing a more detailed plan soon and they are calling for input from users on the issue. Clasen concludes saying "Lets work together and minimize the pain of this transition."