After Twilight Zone and now Futurama, I can certainly see most TV products continuing the trend for TV shows.
It's not any thinner than the fold-out cardboard packaged like Simpsons or X-Files, but is more durable in the long-run.
I wouldn't really mind if the Simpsons changed the format over, since it would still have a slipcase, and on a shelf, you can't tell from the spine which packaging is which, and it won't mess with the "collection look".
But X-Files needs to stay the same to the end (great design people on those sets.
)