that's a not-so-subtle hint.
the preview on the WotC site suggested that the 5 lords from BoVD (well, at least Orcus and Demogorgon) are likely to have been re-statted for FC1, which is just as well since the change from 3.0 to 3.5 happened not long after BoVD was printed.
that leaves us with an additional 9 lords with stats... wonder who they are?
from James's posts above, it should not be hard to infer that the lords from the Demonomicon articles will not have their stats reprinted in the book, so the remaining 9 will be other demon lords...
and i suspect that the chapter on demon lords will be something to the effect of "14 statted lords" "several paragraphs regarding a number of other well-known lords" and finally "a section of quick notes about the rest of the known lords"?