Europe is an entirely different ball-game from the US or the rest of the world. For the longest time, they had few if any emissions regulations (and thus emissions controls) for their diesel engines...and they promoted diesel engines as a more eco-friendly and more economical alternative to traditional gasoline engines for small commuter cars (which is true if we are focused purely on fuel costs and CO2 emissions). When the governments over there started to realize there were some environmental issues with having so many passenger diesel vehicles in congested cities (NOX, particulate matter) they started to put more strict emissions regulations in place, and many car companies (cough...Volkswagen..cough...Fiat) decided to cheat on the emissions testing rather than abide by the rules. Diesel is not on its way out of Europe; it still does, and will continue to see great use in many medium & heavy truck/SUV applications, trains, marine equipment, industrial applications, just like it does here in the States and elsewhere throughout the world. The low-end torque inherent to a diesel engine cannot be beat, even by a gasoline turbo engine, and there are still many applications where such a powerplant makes sense.
The change you will see is that European car-markers will start to move away from putting diesel engines in their small commuter cars for a number of reasons: diesel causes harmful pollution which is exacerbated in high-congestion cities; the Europeans haven't really spent much time or effort in refining/improving diesel emissions controls the way American and Asian companies have; the general public and European governments are very distrustful of anything being marketed as a "clean" diesel engine due to past transgressions by the European car companies (and rightly so).
The American diesel market (at least for trucks and SUV's) seems to be growing; it's no longer limited to 3/4 ton trucks as we now see offerings in full-size and mid-size trucks and SUV's. Most of the American companies seem to have put a lot of effort into making emissions-compliant engines, the only exception to that trend are diesel engines that have European roots (cough...Fiat...cough...Volkswagen). And the reliability on these new emissions-laden systems has been greatly improved from when they first came out. Cost of ownership and purchase is a new challenge for diesel owners, but that's the norm with any new technology when it first hits the market; over time, as diesel trucks become more common, the cost of repairs, parts and maintenance will come down.