I've often wondered if Beech has the ability to restart production of the 1900, given that the aircraft was based on the King Air series, and those aircraft are still in production.
I would imagine much of the tooling for the 1900 still exists on account of how much in common it has with the King Air, but I could be wrong.
Furthermore, Beechcraft would be able to offer upgraded glass cockpit avionics from the King Air, and perhaps even improved engines and better soundproofing inside (similar to what the Q-series uses). They could call it the 1900E.
Then, to update existing 1900Ds, Beech could offer upgrade programs to put in the new avionics on those airframes. (Maybe call it the 1900D+).
That seems like the most realistic option, and then there's always the idea of starting an airplane from scratch, and perhaps using composites to build a larger, roomier aircraft without increasing the weight too much. This might also improve weight and balance, since the 1900s usually can't take 19 people with a bunch of bags in the back.
But either way, given that there is some demand for 19-seat airplanes, and a finite and shrinking supply to take from, I think a newer aircraft is going to be an inevitable need.
I'd take the awe of understanding over the awe of ignorance any day.