Its a waste of space having 4-arrow cursors on the keyboard... they use much more space than a trackball, and little more than a trackpad.

You could place the trackpad on the rear, save a little bit of space from the trackball.

By the way the keyboard concept is for phones as large as the SGS3/S4.
It seems Jolla phone might be a little too narrow and not quite as wide.

As I said before, Jolla should've used much cheaper components or make it more high-end. Remember how much interest the Ubuntu phone got?