The number of 123's on the roads and in our area are definitely decreasing, I am getting ready to do a one last paint job on my 77/240D and with some rust repairs, but this will be the last time.
Another Mercedes diesel is simply out of question for me, the newer ones are simply too expensive to own and operate. Although MB makes number of smaller and simpler diesels for their C class cars, I do not believe that the MB of North America will ever import those cars here. Unlike the 123's the newer MB's are only practical with an extended warranty, once the warranty is out, you better run for cover.
With the gas/diesel prices escalating perhaps we will see some Japanese diesels in more affordable cars.

Vahe
240D/77 350K