American Scientist: Computational Photography

[Fumesucker]

3. One flash could be programmed to fire four times in quick succession

High voltage and current semiconductors have come a long way in the last twenty years, turning a flash on and off in extremely short times is not particularly difficult. In fact most digital camera flashes already fire more than once per shot, which is why standard light triggered slave flashes don't work with many of them, the preflash triggers the slave before the shutter opens and the main flash goes off.

The Sony system communicates with remote remote flashes by pulsing the on camera flash to convey power and timing information to those remote flashes compatible with it, I don't think Sony is alone in that.