"Bluetec" has actually morphed into a catch all for Mercedes that includes all "fuel efficient engines (gas and diesel) from the gas 2.0L turbo inline 4 cylinder all the way up to the 15.6L Detroit Diesel engine....
Keep in mind that the WK CRD was a 49 state vehicle which means it could not be sold new in CA and a handful of other states. The EPA allowed 49 state compliant light duty vehicles up until 2008.5...hence the death of the WK CRD. In 2009 vehicles that were 49 state compliant were kicked out of the "bin" system and manufacturers were gearing up for EPA10 which included the introduction of Selective Catalyst Reduction (SCR) and Diesel Exhaust Fluid (DEF). The WK CRD was in either bin 9 or 10 and those bins were killed at the beginning of 2009, along with Bin 11. Bin 1 = cleanest and Bin 9,10, 11 = dirtiest.
DaimlerChrysler would have need to do a slight redesign on the engine...EGR for instance to meet the 2009 and 50 state compliance and they probably did not think it was a good business decision so they killed the WK CRD.
The WK CRD was DOA. It was never going to be more than a stop gap and was probably a mistake in the long run. Daimler and Chrysler were parting ways and there was never any intention to have the WK CRD meet 2009 and EPA10 requirements (the inclusion of SCR and DEF) or be 50 state compliant.
The vehicle in the article above was a concept and was again DOA.
Daimler and Mercedes had already planned on the WK2 and as you know it shares the same platform as the Mercedes ML350. Only insiders inside Mercedes know how long that relationship will continue.