I guess it depends on what studio the show is made
by, some do not release their material and some
take years and years to release.  And as horrible
as it sounds, paper production artwork is easily
disposed of by studios while the acetate was not :(

I don't think that the cel shops will go out of
business, there will always be cels circulating
the market and a lot of dealers do get cels from
personal collections.  Cels will keep surfacing,
the prices may fluxuate and good shots will
probably come from personal collections so the
prices may be outrageous.  

Studios haven't been using cels for a few years
now so we are seeing the results already.  It is
definately harder to find good cels but they do
show up everyonce in a while.