I would like to see a window environment that offers command mode like vim.
For example, all controls in currently focused window should have a line number faintly visible (one number per line for text boxes with multiple lines). You can highlight change focus to a particular control like changing to a line in vim: `:12`
Tightly packed stuff such as buttons on a tool bar might only one number, with decimal values for the things inside it (or a number each, whatever). You would only need to show the number every 8 buttons or something, people can count the sequence between.
ctrl+w, hjlk for window selection... etc
And while we're at it, repurpose that useless scroll-lock key to toggle to vim mode, so power users can quickly turn it on when they sit down at any computer.