After reading the article I noticed it is over 2 years old. Asked one of the drivers for Jeep at the auto show if Jeep was considering coming out with a decent diesel engine, you know around 4 litre or so, he said no, how unfortunate.

Actually the Jeep Liberty has a diesel engine option.. just can’t get in California because of emissions (NOx)..

http://www.edmunds.com/jeep/liberty/review.html
Third paragraph.. also lower down:

Of special note is that Jeep offered a diesel engine option for 2005 and ’06. This 2.8-liter turbocharged four-cylinder diesel provided 160 hp and 295 pound-feet of torque.

But considering that Chrysler never got the engine into the Wranger, etc.. it is no wonder the company is where it ended up. Many off-roaders were/are clamoring for a diesel in a Wrangler, particularly the Rubicon. It looks like Fiat may have woken Chrysler up though..

http://blogs.insideline.com/straightline/2009/11/chrysler-fiat-press-conference-diesel-jeep-wrangler-coming-in-4th-quarter-2010.html

Another interesting take on the diesel wrangler/ semi custom..
http://www.automobilemag.com/features/great_drives/0912_jeep_aev_j8_milspec/index.html