i here a lot of people talking about how awesome the 8speed auto will be, but with the reputation dodge has with automatics behind diesel engines not holding up very well i think i'd give it some time before I'd be makin any assumptions how great it will be. there's a reason they're the only truck you can get with a manual anymoreand obviously its not because the majority of people want one or the others would still offer one.
i will give dodge credit for stepping out of the box and atleast offering a light duty diesel, although i agree they probably would do better if they stuck with the 5.0 cummins. hopefully gm will release the colorado diesel in the u.s. soon, I'd like ta see how the little truck would do especially if you could turn it up some might be a fun little truck.
FYI
The 8 speed is ZF trans that BMW, land rover, Maserati and other manufacturers have been using for a while. I wouldn't worry about that. And the engine has been in the grand Cherokee in Europe for a while as well.