Yeah, if everybody who is even on the Island has a number associated with them, does that make them all candidates? (BTW, we haven't seen "Lapidus" anywhere yet, right?)
Or are the "candidates" just the ones who correspond to the magic 6 Numbers? Now that Locke is dead-is-dead, does that mean they've succeeded in changing the numbers and maybe Kate/51 will replace Locke/4?