GNOME 3.0 worries

In my opinion (as user) a desktop is there to enable a user to do his/her work efficiently.
Having a stable, reliable and usable platform is what the user cares about. If there is no
coherent well laid out vision of a big leap forward in the user interface, just stick to
incremental improvements.
I can imagine that GTK+ is working on a new ABI. That does not mean that the new GTK+ would be
API-incompatible. If a mere recompilation of GTK/GNOME program is enough to move it to GTK3,
there will be few compatibility issues for Open Source programs.