They're using dvd burners with a blue laser (smaller wavelength...hence more storage).
That's the next generation of dvd burners (up to 22gb per disk), which will be able to store HDTV signal.
Two things however....firstly, they won't be 22gb AND 16x or whatever speed...it'll be EITHER 16x (eventually) OR 22gb. :->
And ofcourse, there are already two groups battling out which format of the blue laser will win (just like DVD-R/W and DVD+R/W). *l*