I believe Cape Air has the largest fleet of Cessna 402s.

This article is actually pretty accurate, but it goes downhill when it
says, "Over the next decade, the company stopped production of all
propeller-driven aircraft, including the 402C." Actually Cessna
continued to make propellor driven aircraft (i.e. the Caravan) just not
piston engine aircraft.

and "The only existing multi-engine small planes are the new generation
of business jets, which cost four times as much as comparable
propeller-driven aircraft." Well there a bunch of new twins being made,
but they just don't seem to be the size that Cape Air needs. Probably
the closest would be a Seneca V.

It makes you wonder though, what will replace these planes in the
future?

Cape airlines scramble to repair Cessnas
FAA sends alert on wing structure - Boston Globe
http://www.boston.com/news/local/massachusetts/articles/2005/03/23/cape_airlines_scramble_to_repair_cessnas/