If I want to emphasize background and foreground in different shots I just take two shots at different focus points.
If I want everything to be in focus I stop down the lens.
I have to agree with the dpreview: what artistic problem does this solve?
I can think of a contrived example where there is no time to make two shots (a basket ball player shooting a hoop) and where you want two parts of the image at different distances both in focus and the rest blurred. You could do it with this device, but I would just use image manipulation.
What I would really like is the blade runner camera (or rather dataformat) since the blade runner picture seems to be a composite of many shots.