Add a metronome to the reviews?
Excellent proposal. DPR actually did use a metronome like toy to test the video AF of a camera a while back. I hoped it would become a regular feature of the video mode tests, since slow or drifting AF is a chief flaw of many video capture devices--especially in the case of some DSLRs, but also with dedicated videocams.
A metronome would be a good way to test how fast AF response in still or video mode, at different light levels and / or ISO settings. These would, of course, be primarily on a constant shutter speed basis, and perhaps at a wide or fixed aperture basis, leaving AF and ISO as the variables.
Time and again, people bicker over whether camera X or Y is better for low light sports or action shots. Often, the tests involve only given focal lengths (perhaps near infinity), so we have no real idea how well the AF or IQ will perform for quick shifts between clos and far objects.
The metronome might consist of a square of "flag" with a letter or image that waves to and fro at a distance of about 10', with the background (at 20' distance) consisting of the same still life objects used for the static scene tests.
The metronome would not be like one used for music, since the AF might stay focused on that continuously, so the metronome's base would have to be rather small or off-frame. A pendulum might also work: perhaps a bottle of brandy or a toy monkey swinging on a string!