They're all now using Look pedals.
This was talked about in depth by Rob Hayles and Jamie Staff on Eurosport after the Hoy pedal incident.
They've had to go to the Look system because as you said the others have now exhausted their supply.
I've been pondering about this. I noticed most sprint riders have been using Look (or Look type) pedals with single or sometimes double straps. I saw one Japanese rider using traditional pedals with clips. I got up off the sofa and had a good look at my nearest Look Keo pedals, trying to work out how they can thread straps through them. Are they modified, or are they special trackie Look pedals?
I can see how Look pedals would allow you to place your foot in the optimum position every time (once you'd spent time finding it), with the straps being an additional security measure. But still, you'd think a traditional pedal with clip & strap would be more secure for the starting effort of a sprinter or kilo rider?