GarugaS
My guess would be that it continues with an all-new set of characters. Or maybe, as Ruyk said, 'You're already better than most Shinigami,' Light will be someone's Shinigami. That would be cool... I would watch that.
That would be awesome either way but more awesome if Misa &/or Light were Shinigami to new Death Note owners cuz Light would definitely make fake rules that would require his human partner become the next KIRA and Misa would most likely do the same w/o Light asking her to do it.