Re: Is the diesel JGC worth the wait?
I was contemplating this same thing. Before buying my Overland, I was heavily considering a Touareg TDI Executive (no cooled seats for $58k? wtf VW, and why must I spend $58k to get keyless access?!).
Anyways, I did some quick math. Right now, regular gas is 3.35 here, and diesel is 3.95 - if you figure the V6 to get about 20 combined mpg, the V8 about 16 combined, and the diesel to get 25 combined, you get roughly 17 cents per mile on the v6, 21 cents per mile on the v8 (or 22 if you run 89 @ $3.50a gallon), or 16 cents per mile on the diesel.
So basically, if you assume that the diesel costs $2k more than the v6, that means to make up that price penalty, you'd have to drive 200,000 miles. That doesn't account for the superior power of the diesel, but it also doesn't account for any of the other variables with owning a Jeep with a diesel (ie, how incompetent is your dealership - and going by the track record of previous Jeeps with diesels, you should be VERY worried about letting a Jeep tech near your truck, many CRD Jeeps died at the hands of Jeep techs being ill informed or not competent with the diesels, potential reliability concerns, etc.)
I would have been very happy with a diesel powerplant, but I wasn't willing to wait. If you're going for the frugal choice, the v6 is the way to go. In the US, we have limited supplies of diesel, and as more diesels are added, the cost delta to gasoline increases. You simply don't save enough on the backend to make up for the initial cost outlay (though the residuals argument is a very strong one, you could likely make up that difference when you sell the vehicle, but it's also possible that the residuals won't differ too much - X5 diesels don't really command much of a premium over gasoline X5s on the used market, same with Mercedes diesel SUVs).
That said, had Jeep launched the WK2 with a diesel in the US, I'd have probably bought one. But they missed their chance, and I'm not about to trade it in early on a diesel.